GM Introduction

DM eyes only

Campaign Overview

The Shadow of Mars is a 5-session campaign set in a fantastical Roman world where the gods are real, auguries matter, and destiny can be changed—or embraced.

The party plays as members of a military unit stationed at a remote frontier fort. When dark omens appear and a powerful artifact is unearthed, they must decide whether to serve Rome, the gods, or their own ambitions.

Levels: Characters start at level 3 and advance to level 7 by the campaign’s end.

Themes: Duty vs. ambition, fate vs. free will, loyalty vs. survival, divine intervention

Setting: The campaign takes place along Rome’s Germanic frontier in 175 AD, in an alternate world where D&D magic exists alongside Roman military discipline and pantheon worship.

Key NPCs

Legate Marcus Aurelius Corvinus – Commander of the fort, ambitious and ruthless
Augur Cassia Liviana – The fort’s seer, troubled by dark visions
Centurion Titus Varro – Veteran soldier, loyal but pragmatic
Tribune Lucius Valerius Maximus – A mysterious figure from Rome with a hidden agenda
Vercingetorix the Red – Germanic chieftain and reluctant ally
Senator Gaius Cassius Brutus – Roman aristocrat with revolutionary ambitions

NPC OGAS Framework (Guy Sclanders Method)

Legate Marcus Aurelius Corvinus

Corvinus wants the Triumph and the consulship that follows it. The spear is his path there: a divine weapon recovered under his command, presented to the Senate before anyone else learns what it is. He will use the party as deniable retrievers, silence the augur quietly, and write the after-action report himself.

What drives everything he does: he owes Brutus money. The kind of debt that means Brutus owns him. This terrifies him in a way nothing military does. You can see it in Session 1, before Lucius arrives – he is performing command to manage something beneath the performance. Watch for the moment he looks at the staircase twice in two minutes. That is not ambition; that is a man managing an anticipated arrival. Once Lucius walks through the gate, the fear goes underground and does not surface again.

He speaks in short sentences with no question marks. When he is angry he does not lose control; he narrows. He will sacrifice subordinates before he sacrifices himself. This is not cruelty: it is a decision he made years ago and has not revisited. Trust this about him completely.

Session role: Blunt Force Nemesis, Sessions 1-2.

Why Corvinus assembled this unit (DM only – click to expand)

He did not want a contubernium. He wanted a toolkit. Each person was chosen for a specific function he needed at the excavation site, and none of them know that is what they were chosen for.

Here is what he was actually thinking when he wrote each summons letter:

Optio: Someone to run the chain of command without asking Corvinus for permission on every minor decision. He trusts competent NCOs more than officers; officers have their own careers to protect.
Tesserarius: Watch-schedule control. He needs the excavation site covered on specific shifts without it appearing in the normal rotation. The tesserarius can adjust the schedule without triggering review.
Aquilifer: The eagle bearer was Metellus, who is dead. The role is vacant and ritually significant. Corvinus needs someone holding it who will follow orders before taking religious initiative. He does not know yet what that will require.
Medicus: Workers have been getting hurt. He needed a medic who would not file official casualty reports that travel up the chain to Carnuntum. The reports would attract attention he cannot afford.
Haruspex: Paterculus has been filing concerning augury results. Corvinus needed a second religious voice at the site – not to override Paterculus, but to have another augur’s signature he can attach to a more favorable reading if the Senate asks questions.
Faber: The excavation needed specialist engineering support that the standard construction crew could not provide. He wanted a faber who could work without drawing on the main construction budget.
Librarius: Documentation control. The site findings need to be recorded in a way that protects Corvinus’s claim to discovery. He needed a scribe who could produce correct-looking records without asking why the dating on a document needs to predate the actual dig.
Explorator: Eyes beyond the north gate. He knew the Germanic tribes would respond to the excavation. He wanted advance warning before it became a military problem.
Sacerdos: The site has religious significance he did not fully understand when he started. He needed someone who could assess it without triggering official temple oversight from Rome.

What Corvinus does not know: There is a frumentarius in his assembled unit. Someone from the Imperial intelligence service is already reporting on the excavation to a handler in Carnuntum who reports to Rome. Corvinus thinks his documentation control covers him; it does not. The frumentarius has been observing and filing since the summons went out. If a player took the frumentarius role, this is their actual situation. Corvinus will not know unless a player tells him – or unless the frumentarius’s reports trigger a response from Rome that arrives faster than expected.

The cover story: Construction oversight. The official letter uses this phrase in every summons. This is not a deception in Corvinus’s mind: it is what he plans to call it afterward, once the spear is secured and the credit assigned. He chose it because it is vague enough to be unfalsifiable and specific enough to explain why a mixed-specialty unit is assembled at a building site. Do not treat it as a cynical lie; treat it as Corvinus making a decision he has already closed.

Augur Cassia Liviana

Cassia is trying to prevent something she has seen, and she cannot say it plainly because no one would believe her until it was too late. She knows what the spear is. She knows what it wants. She knows what she is.

She guides the party toward the right choice rather than telling them what it is – partly because she is protecting them from the weight of knowing too early, partly because she is not certain they will follow if they know everything at once. This is judgment, not deception.

Her secret is the most significant thing in the campaign: she is Mars’s daughter. She has known since she was twelve. She has not decided what to do about it, which is still true right now. Do not rush this reveal. Wait for the moment the party has done something genuine in her presence. Talking is not enough. She needs to see what they do under pressure. When she trusts them with it, the table goes quiet. Let it.

Session role: Information source and moral anchor, Sessions 1-5.

Centurion Titus Varro

Varro wants to finish his last year without burying more men, then retire to the farm he has been planning in precise detail for three years, and never think about the frontier again. He will not get this, but the desire is real and it shapes every calculation he makes.

He supports whoever seems competent. This is not disloyalty: it is twenty years of watching command failures destroy good soldiers. He has seen this before and he will say so. His dark humor is the thing that helps him keep going; do not play it as bitterness. He is weary, not broken.

His secret is not comfortable: he knows Corvinus is compromised. He has known for a while. Twenty years of service make him complicit in staying quiet. When the party gives him a reason to act – not a good argument, an actual reason – he will. Not before. The question players have to ask him is “what do you know about Corvinus that you haven’t reported.” If no one asks, the information sits there through the whole campaign.

Session role: Reliable ally and reality check, Sessions 1-5.

Tribune Lucius Valerius Maximus

Lucius is performing confidence. He has been performing it his entire life, which means he is very good at it. The performance is his protection against the thing he most fears: being discovered as ordinary. He is Brutus’s illegitimate son, desperate to earn what he cannot inherit. His mission: destroy the spear in a way that gives Brutus what he needs without anyone knowing Lucius was involved.

The mask slips in Session 2, Scene 3. That is the window. Before it: smooth, arrogant, unreadable. After it: locked down and dangerous, because he has chosen. During it: the party can reach him briefly if they are watching for the hesitation before “enemies of Rome.” He knows this is not true and for one moment he cannot make himself say it smoothly.

He will betray anyone to survive. This is fear, not sociopathy. He regrets it afterward. Neither fact protects the party.

Session role: Never Present Villain’s agent, Sessions 2-4.

Vercingetorix the Red

Vercingetorix is dying. He has been dying for two years. The sickness moves slowly and he moves faster. He has chosen this campaign as his last one because the spear killed his grandfather and his tribe has carried that wound for three generations. He wants to close it before he cannot.

He will test the party before trusting them. Not necessarily through combat – through what they do when it costs something. He watches for the moment they choose a harder path over an easier one. When he sees it, he gives them everything he has, including the grove location, the ritual, and his grandfather’s history.

His dying admission – that he knew Brutus had contacted two warband chieftains before the siege – comes out only after the ritual, when he has his answer about them. The ritual is the test. He will not tell them before it. Write this in your Session 4 notes: if the ritual succeeded with genuine sacrifice, he tells them. If it did not, he takes it to his grave.

If a shadow-cursed Spartan is in the party: Vercingetorix recognizes Ares-blood in his first genuine look at the character: not in a crowd, not in a briefing, but in a private moment when he can observe without Romans watching. He does not say the word “Ares.” He says something like: “You carry an old war in you. Not Roman. Older.” He does not treat this as threatening or remarkable. He treats it as information he is filing away. The character is, in his assessment, the most theologically interesting member of the unit and the one most likely to understand what the grove ritual is actually doing. He will speak to them directly in Session 4 before the procession, once, without the rest of the party present, and tell them: the grove does not belong to his tribe. It belongs to the forest. His tribe is only its current keeper. He says this because he thinks the shadow-blood will understand what that means in a way a Roman cannot.

Session role: Reluctant ally and living history, Sessions 2-5.

Senator Gaius Cassius Brutus

Brutus believes he is saving Rome. This is the most important thing to understand about him: he is not cynical. He has examined his position from multiple angles and concluded that one man with the right vision preventing a collapse is worth any number of procedural violations. He is persuasive because he is sincere. The arguments are good. The conclusion is wrong.

He never appears before Session 5. Everything he does is through intermediaries: letters, the Tribune, the sleeper agents, the cultists who carry out his remote ritual in Session 4. He has made pacts with Jupiter, Pluto, and Bellona, promising them Mars’s power if they support his coup. He has arranged a Plan B regardless of what the party does in Sessions 1-4.

The party does not meet him until Session 5. Everything they learn before then comes from evidence he left. Read his pattern through what he set in motion, not through his person. He is the shape of the campaign’s political threat, not its face.

Session role: Never Present Villain, Sessions 1-4; present Session 5.

Mars, God of War

Mars is testing them. That is what the entire campaign is, from his perspective: a sustained test of whether these particular mortals are worth what he is about to offer them.

His anger is real but not arbitrary. It is specifically directed at sloppiness, cowardice, and dishonor. A character who stands their ground in front of him without flinching speaks his language without saying a word. He notices this. He will not say he noticed. Do not announce that he noticed; simply play him slightly differently toward that character from that moment on.

His secret, which the party will not discover unless they are paying very close attention at the epilogue: he was quietly satisfied when the corrupted spear was destroyed. It had become a blight on his name. But he cannot say this, because saying it means the test was not real, and the test is always real. This sits in him unspoken. Do not give it away. Let the campaign earn it.

Session role: Divine Antagonist, Sessions 4-5.

Using OGAS in Play

When NPCs appear:

Start with their Goal - what they want THIS SESSION
Use their Agenda - HOW they’ll try to get it
Reveal Objective through multiple sessions
Drop Secret hints for clever players to discover

Example: When party meets Legate (Session 1)

Goal: Get them to retrieve spear → Direct orders
Agenda: Establish authority → Threatens court-martial if they refuse
Objective leak: “Securing this artifact will echo all the way to Rome”
Secret hint: Cassia whispers, “The Legate is not his own master”

If party goes off-script: NPCs pursue their OGAS regardless of party actions. This makes world feel reactive and alive.

The Central Mystery

A cursed artifact called the Spear of Mars has been unearthed near the fort. Legend says it once belonged to the war god himself and was used to kill a divine being. Now it whispers to those who touch it, promising power and glory while slowly corrupting their souls.

The party must decide: destroy it, claim it, or deliver it to Rome?

Master Plot: The Five-Session Arc

This is the shape of the whole campaign. Use it to maintain dramatic coherence across sessions.

Session	Title	Core Question	Escalation
1	Blood and Omens	Do they obey orders or heed the augur?	Personal → Fort-level stakes
2	The Chieftain’s Price	Can they trust the enemy?	Fort → Regional stakes
3	Shadows Over Vindolanda	Can the fort hold when Rome cannot help?	Regional → Imperial stakes
4	The God’s Demand	What sacrifice will satisfy Mars when he descends upon Vindolanda?	Imperial → Divine stakes
5	The Wrath of Mars	Who speaks for Rome when a god demands judgment at the fort?	Divine → Aftermath

Session 1 – Blood and Omens: The party retrieves the Spear of Mars from ruins beneath the fort. First contact with corruption. The Legate wants it; the Augur wants it destroyed. First choice with no clean answer.

Session 2 – The Chieftain’s Price: Vercingetorix approaches with information about the spear’s origin. Tribal and Roman interests collide. The Tribune arrives from Rome with a hidden agenda. The party discovers the spear has already spread its influence beyond the fort.

Session 3 – Shadows Over Vindolanda: Brutus’ agents trigger a siege that cuts Vindolanda off from the world. Germanic warbands surround the fort while sleeper cells sabotage it from within. The party must hold the walls, expose the traitor, and decide whether the spear is a weapon, a bargaining chip, or a liability when the Empire cannot send aid.

Session 4 – The God’s Demand: The siege breaks the boundary between mortal and divine. Mars manifests in the fort’s shrine, demanding the spear be carried into the ruins beneath Vindolanda for a ritual judgment. The party must escort it through burning battlements, negotiate between Legate, Tribune, and Vercingetorix, and offer a sacrifice that will either save or doom the garrison.

Session 5 – The Wrath of Mars: The parade ground becomes a divine arena suspended above the fort. Senator Brutus channels his conspiracy through distant cultists, the Legate and Tribune make their final plays, and Mars insists on an answer. The party’s choices decide whether Vindolanda becomes a martyrdom, a holy site, or the first stone in rebuilding Rome’s future. Three major outcomes remain: the spear is destroyed, claimed by a mortal, or returned to Mars—but now the fate of the fort is entwined with that decision.

The three endings:

Destroy the spear: Mars is appeased but loses his weapon. Rome is safe for now. The party earns honor but no tangible reward. Bittersweet.
Claim the spear: One character becomes extraordinarily powerful and extraordinarily corrupted. This likely ends with that character as an antagonist or tragic sacrifice. Dramatic.
Return it to Mars: The god is satisfied. He grants the party his blessing and departs. Brutus’ conspiracy continues elsewhere—the divine crisis is solved, but the political one now sits outside the fort. Ambiguous.

Combinations and partial outcomes are valid. The key is that every NPC’s OGAS resolves in a way that feels earned by their established character.

NPC Relationship Web

Who knows what about whom. Use this to run every character as a fully-informed actor in their own story.

                        SENATOR BRUTUS
                       (Never Present)
                      /       |        \
              [owns]  /   [sent]  \  [made pacts with]
                    /         |         \
           LEGATE          TRIBUNE       GODS (off-screen)
          CORVINUS          LUCIUS       Jupiter, Pluto, Bellona
             |               |
      [commands]        [suspects]
             |               |
          PARTY ———————————————
             |        [reports to]
      [trusts]              |
             |           AUGUR
          VARRO            CASSIA ——[daughter of]——> MARS
             |               |
      [respects]       [warns about]
             |               |
       VERCINGETORIX ————————
       (ancestral claim to spear)

Key knowledge asymmetries:

NPC	Knows	Doesn’t Know
Legate Corvinus	He owes Brutus money. Brutus wants the spear.	That Lucius is also Brutus’ agent. That Cassia is Mars’ daughter.
Augur Cassia	She is Mars’ daughter. The spear’s true history. Brutus exists.	That Lucius is Brutus’ son. What Brutus’ full plan is.
Centurion Varro	The Legate is compromised. The Tribune is hiding something.	Brutus, Cassia’s heritage, or the divine dimension of the spear.
Tribune Lucius	His mission from Brutus. That Brutus is his father.	That Cassia is Mars’ daughter. Vercingetorix’s dying secret.
Vercingetorix	The spear’s tribal history (three generations). Where the sacred grove is.	Brutus exists. That the Roman augur has divine blood.
Senator Brutus	The spear’s location. That Lucius is his tool. The replica spear ritual.	That Cassia can feel the spear’s divine pull. That Vercingetorix is dying.

Per-Session NPC State Table

What each NPC knows, wants, and is actively doing in each session — whether or not the party engages them.

Session 1

NPC	Where	Goal	Active Move
Legate Corvinus	Fort, principia	Secure the spear for personal glory	Ordering the party into the ruins; monitoring the Augur
Augur Cassia	Fort shrine	Prevent the spear being claimed	Performing continuous augury; leaving warning signs
Centurion Varro	Fort walls	Keep his soldiers alive	Quietly positioning trusted veterans near the excavation
Tribune Lucius	3 days away on the road	Reach the fort before the Legate does something irreversible	Riding hard with a Praetorian escort
Vercingetorix	5 miles north, tribal camp	Recover the spear	Watching the fort; waiting for Roman attention to be divided
Senator Brutus	Rome, his villa	Ensure the spear never reaches Rome’s politics	Writing orders to Lucius; unaware the party exists yet

Session 2

NPC	Where	Goal	Active Move
Legate Corvinus	Fort, publicly humiliated	Recover command and the spear	Cooperating with Tribune publicly; plotting privately
Augur Cassia	Fort shrine	Stop the Tribune taking the spear to Rome	Building a case against Lucius; trying to reach the party
Centurion Varro	Fort, armed and waiting	Protect the party and his unit	Has 6 veterans positioned near spear storage; ready to intervene
Tribune Lucius	Fort, establishing authority	Get spear destroyed without fingerprints on it	Manufacturing a justification to destroy the spear “in the field”
Vercingetorix	2 miles north	Exploit the Roman power struggle to reach the spear	Leading the raid; timing it to coincide with Tribune’s arrival
Senator Brutus	Rome	Receive confirmation from Lucius	Waiting; becoming impatient

Session 3

NPC	Where	Goal	Active Move
Legate Corvinus	Principia war room	Use the siege to seize the spear openly	Reassigns loyal cohorts to “protect” the artifact; orders ration lockdown
Augur Cassia	Fort shrine	Keep the spear hidden and the omens quiet	Conducts hourly auguries, warns the party a traitor opened the gates
Centurion Varro	Outer walls	Keep Vindolanda alive through siege	Rotates exhausted watch shifts, uncovers missing armor from the armory
Tribune Lucius	Quartermaster vault	Destroy the spear without being blamed	Forges evacuation orders, tries to move the spear under cover of night
Vercingetorix	Outside palisade under white flag	Ensure the Romans honor the grove ritual	Sends messengers through tunnels offering aid if the spear is released to him
Senator Brutus	Rome (never present)	Make sure the spear dies with Vindolanda	Activates sleeper agents (including Sextus’ killer); sends orders via raven

Session 4

NPC	Where	Goal	Active Move
Legate Corvinus	Parade ground command post	Reclaim authority by controlling the ritual escort	Arms loyalists, prepares to arrest anyone moving the spear without him
Augur Cassia	Shrine and tunnels	Lead the godward procession safely	Bargains with Mars’ manifestations; channels divine fire away from civilians
Centurion Varro	Escort detail	Keep the party alive through the underfort ruins	Assigns shield wall rotations inside tunnels; ready to kill mutineers
Tribune Lucius	Command tower	Save himself by aligning with whoever survives	Offers to “guide” the party, but plants Brutus’ sigils near the ritual site
Vercingetorix	Under-castra approach	Secure space for Thusnelda’s rite	Stations warriors at choke points to keep Romans honest
Senator Brutus	Remote cult circle in Rome	Hijack the ritual through sympathetic magic	Orders Marius Coda to spill blood at the same time the party descends

Session 5

All surviving NPCs are absent from the divine arena — Mars’ judgment is for the party alone. Their fates are resolved in the epilogue.

NPC Voice Reference

Three characteristic lines per NPC. Read these before every session they appear in.

Legate Marcus Aurelius Corvinus

Blunt. Commanding. Self-interested beneath Roman virtue performance.

“I don’t need your opinion. I need your obedience. There’s a difference.”

“Rome doesn’t run on philosophy. It runs on iron and men willing to use it. Are you willing?”

“I’ll be honest with you because I respect competence: I need that artifact. Help me get it and I’ll make sure the right people know your names.”

Augur Cassia Liviana

Quiet. Certain in ways that unsettle people. Speaks in fragments when the visions press.

“Three nights. The same dream. The spear standing upright in a field of blood, and every person I know kneeling around it. Dreams are not prophecy. But they are not nothing.”

“You want me to tell you it will be alright. I can’t. I can tell you what Mars wants, and you won’t like it. Do you want me to tell you anyway?”

“I have known what I am since I was twelve. I have not decided what to do about it. That is still true.”

Centurion Titus Varro

Economy of words. Dark humour. Trust earned through action, not speech.

“Twenty years. You know what I’ve learned? The men who make speeches about Rome’s greatness are always somewhere else when the bill comes due.”

“I’m not telling you what to do. I’m telling you what I see. What you do with it is your problem.”

“I’ve buried forty-seven men. Every one of them thought it wouldn’t be them. Just saying.”

Tribune Lucius Valerius Maximus

Performs confidence. The performance gets thinner as the pressure rises.

“I appreciate the frontier aesthetic — truly, very authentic — but perhaps we could discuss this somewhere that doesn’t smell of horses and anxiety?”

“My father always said the problem with idealism is that it requires other people to share it. He was usually right. I’ve stopped telling people that.”

“I know you don’t trust me. I don’t blame you. I’m not sure I trust me either, at this point. But I’m telling you the truth right now. For whatever that’s worth from someone like me.”

Vercingetorix the Red

Poetic. Unhurried. Measures people by what they do under pressure.

“Romans name everything they conquer. They think that is how they own it. They are wrong. You can name a river. The river doesn’t care.”

“I have been dying for two years. The sickness moves slowly. I move faster. That has been my advantage.”

“Your kind and my kind have been killing each other for a hundred years. You are the first Romans I have met who asked me what I wanted before telling me what I would receive. That is… unusual.”

Senator Gaius Cassius Brutus

Statesman’s cadence. Rhetorical questions. Completely sincere about everything, including the terrible parts.

“You’ve seen the frontier. You know what Rome looks like from the edge. Does it look like the Republic our ancestors bled for? Or does it look like one man’s property, maintained by other men’s fear?”

“I’m not asking you to do anything illegal. I’m asking you to think about what the law is for. And whether what we have now serves that purpose.”

“History will understand. History always understands necessity. The people who live through necessity — they have a harder time. I accept that. So should you.”

Mars, God of War

Short. Final. Every word the weight of a weapon.

“MORTALS EXPLAIN THEMSELVES. A god listens once.”

“I did not make war because I enjoy it. I made war because without it, what you call civilization does not exist. Remember that the next time you thank a god for peace.”

“You surprised me. That happens rarely. I will remember it.”

NPC Reaction Tables

How each major NPC responds to the three most likely party approaches.

Legate Corvinus

Party approach	Response
Obey and cooperate	Respect, increased orders, occasional genuine gratitude. He’s not cruel to useful people.
Question or push back	Anger first, then calculation. “Is this going to be a problem?” Will find leverage.
Expose or threaten him	Controlled fury. Looks for allies immediately. Will sacrifice anything to protect his position.

Augur Cassia

Party approach	Response
Trust her and ask questions	Opens up completely. Tells them everything she knows, including things that scare her.
Skepticism / dismissal	Patient. “You don’t have to believe me. The omens don’t change because you don’t believe them.” Keeps trying.
Threaten or pressure her	Genuine sadness. Won’t fight back. Will still try to complete her mission through other means.

Centurion Varro

Party approach	Response
Treat him as an equal, ask directly	Straight answers. Everything he knows. Becomes a genuine ally.
Pull rank or give orders	Polite compliance, zero cooperation. He’s seen too many officers to be impressed by rank alone.
Ask him to betray the legion	Won’t. Hard line. Can be convinced to bend rules — never to break the fundamental oath.

Tribune Lucius

Party approach	Response
Expose his agenda with evidence	Negotiates immediately. Offers what he has — access, testimony, knowledge. Coward beneath the performance.
Charm or persuade	Responds well; the mask slips slightly. Wants to be liked. Wants to be understood.
Physical threat	Capitulates fast. Then looks for the first exit. He will betray anyone to survive — but regret it afterward.

Vercingetorix

Party approach	Response
Acknowledge his people’s claim on the spear	Immediate respect. Shares everything: the grove location, the ritual, his grandfather’s story.
Dismiss or ignore his claim	Tests them physically — not violently, but through endurance challenges or blunt confrontation. “Show me you’re worth talking to.”
Attack first	Fights until he respects them, then stops. Offers honorable single combat rather than continued battle. Never runs.

Senator Brutus

Party approach	Response
Engage his argument about Rome	Genuinely engages. This is his favorite topic. He will be persuasive. He will almost be right.
Threaten him with legal action	Completely unconcerned. He has done nothing illegal yet. “Bring your evidence to the Senate. I look forward to the debate.”
Physical confrontation	Does not fight personally. Calls guards immediately, then disappears. Never in the same room as violence he ordered.

Lex Arcana: Adapted Systems for This Campaign

Lex Arcana is an Italian tabletop RPG set in an alternate Rome where the empire never fell. Its investigative framework and virtue mechanics are more suited to Roman play than standard D&D structures. The four systems below are adapted from Lex Arcana and integrated into this campaign. Read this section before Session 0; the systems become relevant from Session 1 onward.

The Exploratores Extraordinarii: Party Authority Structure

In Lex Arcana, the party operates as members of the Cohors Auxiliaria Arcana, imperial investigators with authority crossing provincial lines. This campaign uses a functionally identical structure.

After Session 1, Corvinus formalizes the party’s designation as Exploratores Extraordinarii (special investigators). He does this for his own reasons: it gives him deniability if their actions cause political problems, and it gives them enough authority to act without constant supervision. This is standard practice for a commander who needs things done but does not want to know exactly how they were done.

What this authority grants:

The right to investigate without explaining themselves to local commanders below the rank of legate
Access to temple records and military archives that are normally closed to line soldiers
The right to detain persons of interest for questioning (not indefinitely; Roman law applies)
Official status that makes it illegal for most people to obstruct them

What this authority costs:

They are accountable directly to the Senate if their actions are questioned (which Brutus exploits in Session 4)
Any significant failure is documented and attributed to them, not to Corvinus
They cannot claim ignorance: if they knew something was wrong and did nothing, they are liable

In play: Introduce this designation formally at the start of Session 2. Corvinus hands them a sealed document. He does not explain its full implications. The players should discover the complications of the designation over time, not all at once.

Roman Virtues as Character Mechanics

Lex Arcana uses seven Roman virtues as personality mechanics. This campaign adapts the same system.

The seven virtues:

Virtue	Latin	What it means in play
Virtus	courage and excellence	Standing your ground when retreat is tactically safer; setting the standard in formation
Pietas	duty to gods, family, Rome	Observing religious obligations; protecting civilians; not abandoning your unit
Fides	loyalty and trustworthiness	Keeping your word; not betraying sources or allies; honoring oaths
Iustitia	justice and fairness	Applying Roman law correctly; not punishing the innocent; proportionate response
Clementia	mercy and restraint	Accepting surrender; not executing prisoners without cause; restraint in victory
Frugalitas	discipline and simplicity	Not seeking personal enrichment from official actions; controlling appetites; resourcefulness
Dignitas	dignity and reputation	Maintaining your honor in public; not behaving in ways that shame your rank or unit

How the mechanic works:

At Session 0, each player declares their character’s primary virtue: the one they aspire to most and the one they struggle with most (these can be the same). This declaration is for the DM’s records. The players do not need to publicize it.

Advantage trigger: Once per session, when a character acts clearly in accordance with their declared primary virtue at significant personal cost, they gain advantage on one ability check, attack roll, or saving throw of their choice within the next ten minutes of in-game time. The player declares this before rolling. The DM has final say on whether the action qualifies.

Atonement mechanic: When a character acts clearly against their declared primary virtue in a significant moment (betrays an oath while claiming Fides, shows cowardice under circumstances their character should have held the line, etc.), they take -2 to the relevant ability modifier’s checks until they perform a public or significant act of atonement. What constitutes atonement depends on the virtue violated and the circumstances.

DM guidance: Do not track these mechanically on a spreadsheet. Track them in your session notes. The goal is not to catch players out; it is to create moments where the virtues are tested in ways that feel earned. Signal to players when a virtue moment is approaching, not through narration of the mechanic, but through the situation itself.

Augury as Structured Mini-Game

Lex Arcana has a detailed augury system. This adaptation gives the haruspex or any character with Religion proficiency a structured way to seek divine guidance.

When to use: Once per session. The augury takes 30 minutes of in-game time (a real cost in time-pressured situations). It requires a sacrifice: at minimum, grain and wine; for more reliable results, an animal.

How it works:

The character declares the specific question. The question must be about a future action: “will this approach succeed,” not “what is the enemy doing right now.”
Roll Religion (or Intelligence with Religion proficiency). The DC depends on the question’s specificity.
The DM answers using the tier table below:

Roll	What the DM reveals
DC 13 success	Auspicia secunda (favorable signs) or auspicia adversa (unfavorable signs): a single-word directional indicator
DC 15 success	Auspicia clara (clear signs): what category of obstacle the character should prepare for, without specific detail
DC 17 success	Auspicia perfecta (perfect signs): one specific thing that will make the difference between success and failure
Failure	Auspicia turbata (troubled signs): the omens are unclear; augury cannot be attempted again until the next session

Design note: The DM should answer honestly within the tier structure. This is not a trap mechanic; it is a resource. A DC 17 result that says “the locked door” is a specific, actionable answer that rewards the player’s investment without giving them the entire solution.

Multiple auguries: If multiple party members attempt augury on the same question in the same session, only the highest roll counts. The gods are not asked twice.

Fatum: Destiny as Campaign Mechanic

Lex Arcana gives each character a Fatum (fate statement) at campaign start. This campaign uses the same system.

At Session 0: Each player writes a one-sentence fate statement for their character. The sentence must be:

First-person
A prediction about the character’s future, not a goal (“I will die in service of something greater than myself,” not “I want to become a centurion”)
Something that could be true or false at campaign end
Something the character would believe about themselves

Examples: - “I will make a choice that the histories remember.” - “I will never let another soldier die because I hesitated.” - “I will see Rome from the inside before I die.” - “I will choose my family over my duty when it comes to it.”

The DM’s responsibility: Read every Fatum before Session 1 and identify one moment in Sessions 2 through 5 where each character’s Fatum is tested. Do not announce this to the player. Simply create the situation; the player will recognize it.

At Session 5 epilogue: Each player reads their Fatum aloud. The table collectively decides: did this character fulfill their Fatum, fulfill it in a way they did not expect, betray it, or fail to reach the moment of testing?

Fulfilled: the character earns a named legacy (recorded in the epilogue narrative)
Fulfilled unexpectedly: the character earns the legacy plus one final narrative moment to describe how they discovered what their Fatum actually meant
Betrayed: the character’s epilogue narrative acknowledges the betrayal; this is not punishment, it is story
Untested: the character did not reach their moment; the epilogue is open-ended

Design note: The Fatum system works because it gives players authorship over their character’s arc without giving them authorship over the plot. The campaign determines what happens; the Fatum determines what it means to each character. These are different things and both are valuable.

Investigation Structure: Three Phases

Lex Arcana formalizes investigation into three phases. Add these phase markers to your mental map of Sessions 2, 3, and 4 (the investigation-heavy sessions).

Phase 1: Investigatio (gather evidence)

The party is finding clues, interviewing witnesses, and observing the situation. In this phase: all investigation-related checks (Investigation, Perception, Insight against NPCs, History to contextualize evidence) are made at normal difficulty. The party cannot effectively take Actio until they have at least two confirmed pieces of evidence.

Phase 2: Deliberatio (analyze and form a theory)

The party steps back from gathering and begins interpreting. This is represented by a short rest or an explicit in-character discussion. During Deliberatio, one party member may make a DC 13 Intelligence (Investigation) check to identify which piece of evidence is most significant (the DM confirms or corrects the assessment). The party should exit Deliberatio with a working theory about what is happening and who is responsible.

Phase 3: Actio (act on the theory)

The party acts on their theory. In this phase: if their theory is substantially correct, all ability checks against the primary antagonist or obstacle have a -2 to DC (they know what they’re dealing with). If their theory is substantially wrong, the DM introduces one complication that the correct theory would have prepared them to handle.

Skipping phases: A party can attempt Actio before completing Investigatio or Deliberatio. When they do, add +3 to all relevant DCs and the DM does not correct their theory before the phase begins. This rule rewards patience without making impatience impossible.

DM note: You do not need to announce these phase names to the players. Simply structure each investigation session so that the natural rhythm of play moves through gathering, analysis, and action. The phase markers are a planning tool for you, not a visible mechanic for the table.

Main NPC Skill DC Framework

Full DC tables for all seven main NPCs. See skill_framework.qmd for the design principles behind these tables. Each entry documents: primary approach, signature skill, wrong-approach consequence, temporal gates, and partial success at three levels.

Corvinus: Skill DC Table

Primary approach: Persuasion (appeals to ambition or military necessity)

DC	What you get	What it feels like
Fail	Formal compliance; the order stands; no additional information	He has heard you and decided you are manageable
DC 12	He listens longer; adjusts the order slightly; does not explain why	A small concession, wrapped in authority
DC 15	Reveals his actual concern (the debt to Brutus, obliquely); adjusts to accommodate the party’s need	He has decided you are useful enough to be partly honest with
DC 18	Full disclosure of his constraints; will work with the party rather than command them, within this session	He has decided you are an ally, which is dangerous and temporary

Signature skill: History DC 14 (knowing his career record). He notices when someone has done the research. This gives advantage on all Persuasion checks with him for the session; it also makes him wary that you are a political player, which reduces his trust by one tier after the session ends.

Wrong approach: - Intimidation: Controlled fury. Looks for allies immediately to use against the party. Future Persuasion checks +3 DC. - Deception, if caught: Treats the party as a security risk. Assigns surveillance. Future Insight checks against them with +4. - Appealing to ethics or fairness: He visibly loses interest. “Rome was not built on fairness.” No mechanical penalty; zero progress.

Temporal gate: Corvinus’s real agenda – the debt to Brutus – is only visible in Session 1, before Tribune Lucius arrives and changes everything. Once Lucius walks through the gate, Corvinus locks down completely. He goes into full political mode and will not be partially honest about anything for the rest of the campaign. The window is short. If the party uses it: they get the most useful intelligence in the first session. If they miss it: the debt becomes something they piece together from other sources later.

Partial success text: - 5 below DC: He restates his position more firmly. He got what he wanted out of the exchange: information about what you want. Watch him use it. - Exactly at DC: He gives you the concession. Nothing extra. The relationship has not warmed; he is just not fighting you on this specific thing. - 5 above DC: He gives you the concession and one thing you did not know to ask for: why he made the calculation he made. That is the interesting part. Give it freely.

Cassia: Skill DC Table

Primary approach: Trust signals (honest engagement, no agenda apparent)

DC	What you get	What it feels like
Fail	Public augury reading only; careful, filtered language	She is performing her role correctly
DC 12	Personal interpretation added to the public reading; she stops filtering	She has decided you can handle what she actually thinks
DC 15	Full information access; she names her fears directly; shares the two things she has not said to anyone	She has decided you need to know this more than she needs to protect herself
DC 18 (or: Religion DC 13)	She tells you what she is; what the spear feels like to her; what Mars wants from her specifically	She has stopped performing entirely

Signature skill: Religion DC 13. A character who speaks the language of the gods removes all filtering. She speaks without hedging to someone who understands the divine.

Wrong approach: - Skepticism or dismissal: Patient. She keeps trying. No mechanical penalty; no additional information beyond what she volunteered. - Intimidation or pressure: Genuine sadness. She will not fight back. She will still try to complete her mission, now without the party. - Deception (claiming false divine knowledge): She knows immediately. “That is not true. Why are you saying it?” Relationship resets to Stranger tier; she will not be deceived a second time.

Temporal gate: Cassia’s true identity as Mars’ daughter only becomes available in Sessions 3-4, and only after the party has done something genuine in her presence. Talking is not enough: she needs to see what they do under pressure. Before that moment she simply has not decided to trust them with it. The window does not close permanently: it opens when they earn it, and not before. Do not force this. Wait for the moment that earns it.

Partial success text: - 5 below DC: She gives you the filtered version. It is accurate. It is also incomplete. Do not flag the incompleteness; let them notice it. - Exactly at DC: She gives you the truth she is comfortable sharing. That is real trust. Treat it as such. - 5 above DC: She gives you the truth and the cost of knowing it. What it feels like to carry what she carries. That is the moment the table goes quiet. Let it.

Varro: Skill DC Table

Primary approach: Directness (no rank performance, no flattery, ask plainly)

DC	What you get	What it feels like
Fail	Polite compliance; he does what is ordered; nothing extra	He has decided to work with you at minimum viable engagement
DC 12	He tells you what he sees; no interpretation added	He has decided you can handle the unfiltered situation
DC 15	His assessment of every NPC in the scene; what he would do if he were running it	He has decided you are worth preparing correctly
DC 18	What he knows about Corvinus’s compromise; what he has been protecting the party from without saying so	He has decided you are people he trusts

Signature skill: Athletics DC 12 OR any military tool proficiency. He evaluates people by capability. A character who demonstrates practical military competence (in his presence, not just on a sheet) auto-advances to Trusted. No Persuasion check needed.

Wrong approach: - Pulling rank or giving orders: Polite compliance, zero cooperation. He has seen too many officers. Persuasion checks with him for the rest of the session are at +3 DC. - Deception, if caught: DC 11 passive Insight catches it. Permanent wariness: all future DCs with Varro increase by 3. Recovery requires demonstrated military competence (specific action, not another roll). - Flattery or appeals to his career: He stops talking. Polite, final. The conversation has ended. - Asking him to betray the legion: Hard refusal. He will bend rules (cover for a necessary action, look the other way once). He will not break the oath. This line is permanent and does not shift regardless of relationship tier.

Temporal gate: Varro’s knowledge of what Corvinus has been hiding only becomes available after Session 2, once he has decided the party is worth trusting with it. He does not volunteer it: he waits for someone to ask the right question. The right question is “what do you know about Corvinus that you haven’t reported.” The window does not close on its own: he is simply waiting for someone to ask correctly. If nobody asks, the information sits there and the party navigates Session 3 without it. That is a real cost.

Partial success text: - 5 below DC: Facts only. No interpretation. He is giving you the raw material and waiting to see what you do with it. - Exactly at DC: Facts plus his read of the immediate situation. This is Varro being useful. - 5 above DC: His full tactical thinking, offered peer-to-peer. What he would do and why. This is what it sounds like when Varro actually trusts someone.

Tribune Lucius: Skill DC Table

Primary approach: Variable (he responds differently to different approaches; reading him first is valuable)

DC	What you get	What it feels like
Fail	Smooth deflection; official position restated; performance maintained	He has categorized you as manageable
DC 12 (Persuasion)	He acknowledges the subtext; does not admit anything; adjusts his position slightly	The performance has a small crack
DC 15 (Persuasion or Insight)	He drops the performance for one sentence; says something true; immediately recovers	You have reached him briefly
DC 18 (or: expose evidence of his mission)	He negotiates immediately; offers what he has; becomes a collaborator out of self-interest	He has calculated that you are more useful as an ally than as an obstacle

Signature skill: Insight DC 15, but only in Session 2 Scene 3 (temporal gate). This is the moment he is most uncertain about his mission; this check reveals the hesitation and opens the negotiation path that would not otherwise exist.

Wrong approach: - Charm without substance: He responds well, the mask slips slightly. But charm without leverage yields nothing actionable. He will be pleasant and useless. - Physical threat: He capitulates immediately. Then looks for the exit. He will betray the party the first opportunity he safely can. Use only if you want short-term compliance and long-term instability. - Appealing to his Roman virtue: He is moved, briefly. Then remembers his mission. Then becomes more defensive than before because you have touched something genuine and he cannot afford to follow it. Net result: harder to reach.

Temporal gate: Lucius’s moment of genuine doubt is Scene 3 of Session 2 only. Before that: his performance is fully intact, there is nothing to read. After that scene ends: he has made his decision and locked it down. The DC 15 Insight check exists only inside that window. Miss it and negotiation becomes confrontation as the only path forward. The window closes because he chose – not because time ran out. He closes it himself. That distinction matters: if the party catches him in time, they are catching a man in the act of choosing.

Partial success text: - 5 below DC: He tells you what he wants you to think. Fluid, professional. Nothing useful. - Exactly at DC: Something true arrives, wrapped in enough performance that finding it takes work. The players feel like they are doing archaeology. That is correct. - 5 above DC: He tells you something true, drops the performance around it, and immediately regrets it. He is more honest now and also more dangerous. Do not soften either half of that.

Vercingetorix: Skill DC Table

Primary approach: Acknowledgment (recognizing his people’s claim and position before asking for anything)

DC	What you get	What it feels like
Fail	A test: he asks the party to demonstrate something before continuing	He has decided they need to earn the conversation
DC 12	He acknowledges the party as worth speaking to; shares surface information about the spear	He has decided to start
DC 15	Full sharing: the grove location, the ritual structure, his grandfather’s history with the spear	He has decided to help
DC 18 (or: acknowledge his dying; or: Germanic language proficiency)	His dying admission: he knew what Brutus’s plan would mean and chose not to tell anyone; his reasons	He has decided to be honest even about the uncomfortable parts

Signature skill: Germanic language proficiency auto-advances past the first tier with no roll. Additionally: demonstrating that you spared someone during the raid (any Germanic prisoner or wounded combatant) advances the relationship by one tier automatically.

Wrong approach: - Dismiss his claim: He tests them. Not violently; through a direct challenge that requires physical or social demonstration. If they meet the challenge: continues. If not: the conversation does not progress this session. - Persuade without doing anything first: DC 18 and yields nothing useful even on success. You cannot talk your way past him; you have to act. - Attack first: He fights until he respects them. He will offer honorable single combat rather than continued battle. He never runs. If defeated honorably: the relationship advances to Trusted automatically. If defeated dishonorably (multiple attackers, ranged, ambush): he is a permanent enemy. - Promise something Roman on behalf of the Senate: He listens. His expression does not change. He has heard Rome’s promises before.

Temporal gate: Vercingetorix’s dying admission only becomes available after the grove ritual, when he has seen what the party actually did when the cost was real. Before that he does not know whether they deserve to hear it. This is not withholding: it is honest. He will not give that trust to people who have not demonstrated they can handle it. The ritual is the test. If they pass it – genuine sacrifice, not a token – he has his answer. The window does not close; it opens.

Partial success text: - 5 below DC: He tests you. The information is behind the test, waiting. Let the test be real. - Exactly at DC: He gives you what you acknowledged. Exactly that. He is precise. - 5 above DC: He gives you the information and one thing you did not know to ask for: a route, a warning, a name. This is Vercingetorix being generous. It does not happen often. Notice it.

Senator Brutus: Skill DC Table

Note: Brutus is never directly encountered before Session 5. Skill interactions with him are indirect: gathering information about him, interpreting his messages, anticipating his moves.

Primary approach: Investigation and History (he leaves evidence; reading it correctly is the skill)

DC	What you get	What it feels like
DC 12 (Investigation, any Brutus evidence)	His nominal political position; that he is connected to the frontier situation	Confirmed: he exists and is involved
DC 15 (History, or Investigation of specific Brutus materials)	His actual political goal: restoring the Republic; his method: using divine instability to create a leadership crisis	Understanding his logic, which is internally consistent and not stupid
DC 17 (History + prior evidence assembled)	That he has made pacts with other gods; that his Plan B exists regardless of what the party does in Sessions 1-4; the specific thing he cannot survive politically	Complete picture: what he is, what he wants, and where he is vulnerable

Signature skill: History DC 17 to correctly identify his full political position from evidence alone, without any direct interaction. This is the highest difficulty in the main NPC framework; it requires prior evidence-gathering and multiple session investment.

Wrong approach: - Confronting him via legal channels: He is completely unconcerned. He has done nothing illegal. He is genuinely looking forward to the debate. - Physical threat or confrontation: He is never in the same room as violence he ordered. His guards are immediately present. He disappears. He will not be caught this way. - Attempting to negotiate with him (if contact is made): He engages genuinely and is persuasive and almost right. He will not be moved from his course by argument; he has already had every argument. What changes him is evidence that his plan is failing, not that it is wrong.

Temporal gate: The DC 17 result about Brutus’s divine pacts is not available before Session 4. Not because the information is hidden: because Plan B has not been executed yet. There is no evidence to find. Earlier sessions yield DC 12 and DC 15 results at best, and that is the honest limit of what the evidence supports. When Session 4 begins and the sleeper agents start moving, the picture completes. If the party investigates then, the evidence is there. The window does not close: it opens when the events create the trail.

Partial success text: - 5 below any DC: He exists. He is connected. That is all you can confirm. It is not nothing; it is a thread. - Exactly at DC: You have what the DC describes, clearly. He has handed you a problem without its solution. That is the right feeling. - 5 above DC: You have the picture and the one specific thing you can do about it: the vulnerability he does not know you found. Deliver this quietly. It should land.

Mars: Skill DC Table

Note: Mars is encountered directly only in Sessions 4-5. Skill interactions before that are through intermediaries (Cassia, Paterculus, the augury system). The tables below apply to direct interaction.

Primary approach: Demonstration (words without deeds mean nothing to Mars)

DC	What you get	What it feels like
Fail	He gives one more trial. He does not accept failure as an answer; he accepts it as the first attempt.	He has seen this before
DC 14 (Persuasion backed by a prior deed)	He pauses. He is listening. He does not yield; he waits.	He has decided you are worth the pause
DC 17 (Persuasion backed by sacrifice)	He adjusts his demand; the trial terms change; the outcome range expands	He has acknowledged your argument
DC 20 (Persuasion backed by both deed and sacrifice; or: Option C three-argument success)	He concedes one thing he would not have otherwise; explains his position in a way he would not explain to most mortals	He has decided you are worth the explanation

Signature skill: Demonstrating Virtus (the virtue mechanic) during his presence auto-advances by one tier. There is no roll. He notices courage because courage is his domain. A character who holds their ground when retreat would be safe, in his presence, without flinching, is already speaking his language.

Wrong approach: - Arguments without deeds: He listens once. Then gives the trial. “Mortals explain themselves. A god listens once.” - Deception: He knows. He does not punish it; he simply does not engage. The trial remains. The option that deception was meant to bypass is now unavailable. - Appeals to Roman virtue (without demonstrated virtue): “You invoke the words. Invoke the deeds.”

Temporal gate: Mars is persuadable only in the window after the three kneeling witnesses kneel and before the final trial begins. That window is one conversation. Outside it: the trial proceeds on its original terms and arguments do not move him. The reason is simple: he opens to genuine preparation and closes to delay. If they used the procession to prepare – kneeling witnesses, actual sacrifice, clear intent – the window is real. If they treated the procession as a formality, the window never opened.

Partial success text: - 5 below DC: He gives another trial. This is not punishment: this is how he says “try again.” Do not frame it as failure at the table. - Exactly at DC: He adjusts. The outcome range shifts by one option in the party’s favor. That is a real concession from a god. Name it. - 5 above DC: He explains something he does not explain to most people. Not mercy: understanding. He has decided they have earned it. Take a breath before you describe this. It matters.

Cross-Session Integration: Cascade Unlock Master Table

Track these across sessions. A player who hit DC 17 in Session 2 has earned what Flavus brings in Session 4. Do not let that payoff disappear.

At the start of each session, check the “Session achieved” column. Any entry from a previous session that was hit: note it in your session record before play begins. The unlocks do not announce themselves. You deliver them at the right moment.

Session achieved	DC required	Skill	What it unlocks	When it activates
Session 1	DC 17 History (Hall of Shields)	Intelligence (History)	Investigation DC 15 to identify Legion XVII markings on ruins armor; opens the question of who brought equipment that should not exist here	Any time party examines ruins equipment in Sessions 1-3
Session 1	DC 14 Insight (Corvinus, before Tribune arrives)	Wisdom (Insight)	Corvinus’s fear is visible beneath his ambition; every future negotiation with him can reference the debt he is managing; gives context for his Session 3-4 behavior	Sessions 2-4 whenever Corvinus is a negotiation target
Session 1	DC 13 History (Hall of Shields, 5-above)	Intelligence (History)	The tribal arrangement implies a single authority over all four groups; Session 3 answers it; players who hit this can make the connection themselves when Thusnelda explains the grove	Session 3, grove arrival
Session 2	DC 17 Leadership (wall defense, “Flavus named”)	Wisdom (Insight) or Charisma (Persuasion during battle)	Flavus, 19 years old, first posting: he appears in Session 4 as an escort volunteer without being recruited. Write his name in your session record now.	Session 4, procession preparation scene
Session 2	DC 14 Insight (Tribune Lucius, Scene 3 only)	Wisdom (Insight)	Negotiation DC with Lucius in Scene 4 drops from 17 to 14; player can invoke the hesitation directly: “You paused. You know this is not true.”	Session 2, Scene 4 only; closes at end of Scene 3
Session 2	DC 15 Germanic Tribes (knowledge check)	Intelligence (History)	First Persuasion check with Vercingetorix is DC 12 instead of DC 15; character knows not to offer Roman status and knows the correct opening move	Sessions 2-3 whenever Vercingetorix is a social target
Session 3	DC 14 Insight (Vercingetorix, after grove ritual)	Wisdom (Insight)	He reveals that Brutus’s agents contacted two warband chieftains surrounding Vindolanda; Sigrun knows which chieftains; party can split the siege in Session 4	Session 4, siege preparation; opens targeting of specific chieftains
Session 3	DC 17 Divine Signs (knowledge check, pre-campaign)	Wisdom (Religion)	Paterculus’s Session 4 omen document is interpretable at DC 13 Religion instead of DC 17; party understands Mars is arriving on schedule, not destroying on impulse	Session 4, when Paterculus shares written omen document
Session 4	DC 13 Insight (spear weight shift on Elder Stair)	Wisdom (Insight)	Advantage on first Persuasion check with Mars in the antechamber if player mentions the spear’s direction; Mars finds it interesting that they were paying attention to what the divine object was doing	Session 5, Option C first argument only
Session 5	DC 13 Insight (Mars’ first look, opening moment)	Wisdom (Insight)	The character Mars looks at first has advantage on the first Option C argument if they open with the grove sacrifice; the look closes when Mars speaks	Session 5, Option C; window closes when Mars addresses the party
Session 5	DC 12 Insight (Varro holding back, epilogue)	Wisdom (Insight)	Varro says the one thing he has been holding back across five sessions; one sentence written before Session 5 based on the actual campaign; give it to the player who paid attention to Varro	Session 5 epilogue only; requires Varro alive and present

How to Use This Table

Before Session 1: skim all entries and note which depend on Session 0 choices (language proficiencies, backgrounds).

Before each session: check the “Session achieved” column for every entry from prior sessions. Mark which ones the party actually hit. Those are active.

During play: deliver unlocks at the listed activation moment. Do not announce them as rewards. Just play the world as if those things are true, because they are.

If the party missed a check: the unlock does not activate. The alternative path is documented in the relevant chapter’s Skill Audit section. No dead ends: different tool, different door.

The Unit: NPC Role Holders

Every role in the vexillatio extraordinaria is filled at campaign start: either by a player character (selected at Session 0) or by an NPC. The NPC holders are not shopkeepers. They are colleagues. They attend the same briefings, eat at the same table, and have opinions about the party’s decisions that they will share without being asked.

Run them as if they were other players at the table. They remember things. They have bad days. They want things from the party and will ask for those things directly. When they die, play the moment: do not summarize it.

Master Role Holder Table

Use this table before each session to check which roles are PC-held and which are NPC-held. Update it when roles change hands or become vacant.

Role	Default NPC	Vacancy likely	Trigger
Optio	Varro	Session 4	Siege breach defense; high risk
Tesserarius	Decanus Arvina	Session 3	Departs with Tribune; deliberate farewell sabotage
Aquilifer	Gaius Metellus	Session 1 (already dead)	Found dead at ruins entrance; opening scene
Signifer	Publius Afer	Session 2	Tribune’s financial scandal; arrested or flees
Cornicen	Libo	Session 4	Siege arrow casualty; horn falls in the mud
Medicus	Cassia	Session 3 or 5	Sacrifice seed or Session 5 choice
Haruspex	Paterculus	Session 4	Siege; will not leave the shrine
Faber	Rufus (trader)	Survives unless targeted	No scheduled vacancy
Librarius	Nerva	Session 2	Forgery arrest; Tribune’s exit
Explorator	Flavus (if unlocked)	Session 5 optional	Returns from forest mission
Frumentarius	Decius Turbo	Session 3	Revealed; party decides what to do with him
Sacerdos	Paterculus (doubles)	Session 4	Same as Haruspex vacancy
Flamen Martialis	Vacant at start	Session 3 (PC can fill)	Available after grove ritual
Capsarius	Aemilia	Survives unless targeted	No scheduled vacancy
Custos Armorum	Brutianus	Session 3	Bribed; flees with Tribune

NPC Peer Behavior

For each NPC role-holder, the following structure gives you what you need to run them as a peer rather than a prop.

Varro (Optio)

What he talks about unprompted: The unit’s discipline, which soldiers are slipping and why, what Corvinus said at this morning’s briefing and whether it makes sense to him. He thinks out loud about command decisions, not to complain but to process them.

What he wants from the party: Backup when he makes a call the soldiers do not like. He will not ask directly; he will mention the situation and wait to see who offers.

What he does if ignored for a full session: He runs the unit anyway. He makes the drill happen, the watch assignments happen, the casualty paperwork happen. He notes that the party was occupied elsewhere. He will reference this later, without reproach, in a way that shows he noticed.

What he notices about the role PC: If someone holds the Optio role, Varro treats them as a peer in command and is genuinely interested in how they handle the soldiers. He will disagree with them when he thinks they are wrong. He will back them publicly when they are right even if he had doubts.

Voice: Short sentences. Active. He does not explain his reasoning unless asked. “The east postern is down a guard. Who do you want me to pull?” not “I was thinking that we might want to consider some options regarding the current staffing situation.”

Cassia (Medicus)

What she talks about unprompted: Her patients. Not by name (medical confidence is real and she observes it) but in general: “I have someone in sick bay who is not improving the way they should” or “the fever pattern changed this morning.” She processes her work through speech.

What she wants from the party: Someone who will tell her what they know about the ruins and what they found there. She has been watching the corruption symptoms. She needs information to understand what she is treating. She will ask once, clearly, and not press if refused. She will not forget.

What she does if ignored: She keeps treating patients. She makes notes in her medical log that become significant in Session 4 if the party ever asks to see them.

What she notices about the role PC: If someone holds the Medicus role, she trains them thoroughly and treats them as a professional. She will share the locked document about field poisons with them at Trusted tier. She will tell them about the corruption symptoms at Ally tier.

Voice: Precise and clinical about bodies, warmer about people. She uses Latin medical terms without apology and translates them without condescension. “The wound is suppurating: infected. We have three days before I have to make a decision about the arm.”

Paterculus (Haruspex and Sacerdos)

What he talks about unprompted: Omens, but not in the way a superstitious person talks about them: technically, like a professional reviewing data. “The liver reading this morning was ambiguous in the lower left lobe. That configuration corresponds to leadership uncertainty. I am not telling you what to do with that; I am telling you what the reading said.”

What he wants from the party: Someone to tell him what is actually happening in the ruins, because the omen pattern he is seeing does not match anything in his reference texts and he is not comfortable with that. He will not admit the discomfort directly, but the frequency with which he brings up the omens reveals it.

What he does if ignored: He observes the festival calendar, maintains the shrine, and files what he files. He does not escalate unprompted. He does escalate when something forces his hand, which happens in Session 4.

What he notices about the role PC: If someone holds the Haruspex role, he is collegial but watchful. He wants to know if they have been trained correctly. He will ask test questions about the libri haruspicini in the first session. If they know the answers, the relationship becomes genuine professional respect quickly.

Voice: Measured. Never alarmed in his phrasing even when alarmed in fact. “The signs continue to be unusual” is how he describes the gods preparing to eat the fort.

Arvina (Tesserarius)

What he talks about unprompted: The watch log and its anomalies. He has noticed the same three irregular soldiers that the Tesserarius role entry describes. He brings these up carefully, testing whether anyone is interested in taking the information seriously.

What he wants from the party: Someone to investigate the watch irregularities with him rather than filing a report that will disappear into the legate’s desk. He is not sure who to trust and is waiting to see who asks the right questions.

What he does if ignored: He continues maintaining the watch schedule and filing the log. He makes a decision about the irregular soldiers that he will carry into Session 3, when it has consequences.

What he notices about the role PC: If someone holds the Tesserarius role, he hands over clean documentation on day one and gives them one warning: “The east postern at the second watch. Look at it yourself before you believe what the log says.”

Voice: Efficient and slightly tired. He has been doing this long enough that he no longer explains things that seem obvious to him. He sometimes forgets that they are not obvious to others.

Decius Turbo (Frumentarius)

Note: Turbo holds this role if no PC is a frumentarius. He is present but not introduced until Session 2. His introduction is triggered by a party action that crosses into his intelligence remit.

What he talks about unprompted: Supply logistics, convoy schedules, grain storage. He is pleasant, competent, and professionally interested in everything. He asks questions that seem like small talk and are not.

What he wants from the party: To understand what they know and what they are going to do with it. He is not hostile. He is calibrating.

What he does if ignored: He files his reports and waits. He will not volunteer information. He will not block the party directly. He will be exactly as helpful as his orders require him to be, which is less helpful than it looks.

What he notices about the role PC: If a PC is the frumentarius, Turbo does not exist as an NPC: the PC is Rome’s intelligence asset in this unit. The DM should have a private conversation with the frumentarius PC about this before Session 1.

Voice: Friendly and precise. He remembers details about people and references them in ways that make conversation feel personal. This is professional behavior, not warmth, but it is indistinguishable from warmth until it becomes important.

Aemilia (Capsarius)

What she talks about unprompted: What she is running out of and what she needs more of. She thinks in supply terms: “I have bandage linen for approximately two significant engagements. After that we are improvising.” She also talks about individual soldiers by their injuries, not their names: “the man with the arrow shoulder” is someone she is tracking closely.

What she wants from the party: Valeria’s herbal stock, specifically the items that Valeria does not sell to soldiers directly. Aemilia knows the herb trader’s actual inventory is larger than what she shows military buyers. She cannot prove this but she knows it. A party member who can negotiate with Valeria as a peer (not as a customer) is useful to her.

What she does if ignored: She treats whoever needs treating and keeps her log current. She is the least politically involved of the NPC role-holders and the most reliably present.

Voice: Practical to the point of seeming blunt. Not cold: she makes eye contact and means what she says. She just does not spend words she does not have.

Brutianus (Custos Armorum, Sessions 1-3 only)

What he talks about unprompted: Weapons condition, ammunition levels, the quality of the last iron shipment. He is competent and appears conscientious. He is also bribed.

What he wants from the party: For them to not look at the condemned stock too carefully. He will find reasons to redirect attention away from it. These reasons are usually legitimate enough that they do not stand out.

What he does if the party examines the condemned stock: He accounts for the discrepancy with a plausible explanation (disposal is behind schedule; the numbers were entered wrong; he was going to file a supplementary report). The explanation is smooth because he has rehearsed it. DC 15 Insight to notice it is too smooth.

Voice: Helpful, slightly eager. He wants to be seen as doing his job well. He is doing his job well, except for the one thing he is not.

He leaves in Session 3. His departure and the armory discrepancy become apparent within the same session. Do not make the connection explicit for the party: let them make it.

New NPCs: Publius Afer, Libo, Nerva, Metellus

These NPCs are present from Session 1 but are secondary until their departure or death creates a vacancy. Brief notes for each:

Publius Afer (Signifer): Quiet, meticulous, clearly uncomfortable about something. He handles the ledger with care and the departures with too much precision. He knows about the debt leverage situation in the ledger. He is not responsible for it; he is afraid of it. In Session 2, the Tribune’s financial scheme puts him in an impossible position and he chooses the path of least consequence, which is wrong. His departure is not heroic.

Libo (Cornicen): The most straightforwardly likeable NPC in the unit. He plays dice badly and knows it, drills the signals vocabulary with anyone who will let him, and has a superstition about ravens that turns out to be correct. He dies in Session 4 doing exactly his job. The horn falls but the signal he sent landed.

Nerva (Librarius): Precise and privately resentful that his skills are being used on frontier paperwork instead of something in Rome that matters. He is the most politically aware of the secondary NPCs: he knows about Brutus’s network from the documentation he processes, not from intelligence. He is not loyal to Brutus; he is loyal to whoever he thinks will win. In Session 2, the Tribune presents a version of winning that looks more convincing than anything Corvinus has offered. This is why he ends up in the wrong place.

Gaius Metellus (Aquilifer): Dead before Session 1 begins. You know three things about him: he was competent (the legate personally selected him), he found something in the ruins (his hands had soil on them when they found the body), and the wound that killed him was not from the front. Let the party learn these things through investigation if they look. Do not hand them over.

When a Role Becomes Vacant

When an NPC role-holder dies or leaves, say it directly to the players. Do not abstract it. “Libo is dead. The cornicen role is unfilled.” Then state the mechanical consequence from the role entry in Unit Roles. Then move on.

The emotional reality is played, not skipped. If the party was close to Libo (because you ran him as a peer and let them get close), the moment has weight without you adding narration about how sad it is. The absence does the work.

A player character can step into a vacant role if they meet the prerequisites and if the circumstances allow the transition. A siege is not the right moment to process paperwork; the morning after the siege is. When a PC takes over a role, they inherit the NPC’s contacts, tools, and outstanding complications. This includes everything the NPC was managing that they did not finish.

Player Character Variants

Some characters arrive at Session 0 with backgrounds that interact with the campaign’s core systems in specific ways. This section is DM-facing: the player sees the flavor in peoples.qmd; the mechanics below are yours to deploy when they become relevant.

The Shadow-Cursed Spartan (Shadar-kai)

Three systems interact with this origin. Run all three; they reinforce each other.

The Mars/Ares tension. When this character is within 30 feet of the Spear of Mars for the first time (Session 1, the vault), describe a sensation of recognition that is not warm. The spear categorizes what it feels in them as Ares-blood, not Mars-blood. Roman doctrine treats these as equivalent. The gods do not. Cassia is present or nearby; she notices. She does not comment immediately. She files it. When you need a private conversation between Cassia and this character (ideally Session 3, when there is space for it), this is what she has been holding.

Mechanical expression in Sessions 4-5, when the party is in Mars’s direct divine presence: this character makes Wisdom saving throws against divine awe at disadvantage (the divine presence is Mars, and the blood knows the difference). They also have advantage on Charisma checks when dealing with Mars directly (Ares-blood speaks to war-gods in a register those gods recognize). Both effects are active. Do not choose between them.

Corruption divergence. The standard corruption track assumes a mortal soul being progressively claimed by a divine force. This character’s soul carries a prior claim from Hades’ compact, which interferes with Mars’s corruption. When they would gain a corruption level from a divine source (the spear, the grove, Mars’s direct attention), they first make a DC 13 Charisma saving throw. On a success: the new corruption does not take hold (Hades’ prior claim deflects it). On a failure: they gain the corruption level normally, and gain one shadow-curse manifestation from the list below. On a natural 1: they gain two corruption levels.

Shadow-curse manifestations (choose based on what fits the scene):

Their shadow acts independently for one scene, moving slightly out of sync with the body. Perception DC 12 for anyone in the room to notice.
They go briefly translucent in direct sunlight: DC 13 Constitution saving throw or 1d4 necrotic damage as the light finds less of them to touch.
For one session, they cannot benefit from the Help action or flanking bonuses (the shadow is not fully anchored to the material plane).

Shadow stage tracking. Maintain a separate tracker for this character alongside the corruption tracker. Stages run 0-4. Starting stage: 0. Announce stage changes immediately and directly: “Your shadow has moved. Open Stage [N].” Do not delay this for dramatic effect; the collapsible text IS the dramatic effect.

Worsening triggers: - Two consecutive sessions without a fading reset: +1 stage (mark the first miss session; the second miss triggers the move) - Three accumulated shadow-curse manifestations (from the corruption divergence section above): +1 stage - Both conditions in the same session: +1 stage, not +2; stage progression has a ceiling of one per session

Lessening triggers: - Stages 1-2: three consecutive sessions with the fading mechanic successfully reset each time: -1 stage - Stage 2+: the grove ritual (Session 4 or as a side mission): -1 stage - Stage 3+: sensation alone cannot reduce stage; requires ritual or divine intercession - Stage 4: grove ritual drops to Stage 3; from Stage 3 normal recovery applies

Important: corruption divergence and shadow stage are linked but not the same. A character can have high corruption and low shadow stage (if they have been living intensely while being claimed by Mars) or low corruption and high shadow stage (if they have avoided divine contact but neglected sensation). These combinations produce different story shapes; both are valid and worth pursuing.

The fading mechanic. If the character goes a full session without experiencing a moment of intense sensation (combat damage exceeding 10 HP, a significant emotional scene, a moment where they describe feeling something strongly), apply a minor fade at the session’s end: disadvantage on Perception checks at the start of the next session until something resets it. This resets immediately upon any intense moment. The intent is not punishment; it is pressure that creates roleplay opportunities. When it resets, note it briefly: “The world comes back into focus.”

Three moments across the campaign have specific effects on this mechanic:

Session 1, first combat damage: Something in the blood recognizes this world. Advantage on all Perception checks for the rest of that session.
Session 4, grove encounter: The shadow at the tree line reaches toward them specifically. Full reset of the fading mechanic. If the character moved toward the tree line, they hear a phrase in old Laconian Greek: “Oupo. Ouk enthade.” (Not yet. Not here.) If they understand Laconian Greek, they understand it immediately. If they do not, they understand the shape of it: the words are not a threat and not a welcome. They are an accounting. Something is tracking when this person will be ready to cross and has checked: not yet, not in this place. The phrase is the grove’s message, not Hades’ directly. It is old enough that the distinction has blurred.
Session 4, Libo’s death (if they witness it): The fading mechanic is suspended for the rest of the campaign. They have felt enough. The compact has been satisfied on its own terms. Note this on your session tracker; it changes what the fading mechanic costs them in Sessions 4 and 5.

Death ruling. If this character dies during the campaign, they do not simply go to wherever the dead go. Hades’ compact has a prior claim. On a failed death saving throw that would kill the character permanently, they make one additional saving throw: DC 14 Charisma. On a success: Hades accepts the soul directly and holds it. The character is dead to the world but not gone: their shadow persists at the place of death for one full session, visible to anyone who knows how to look (DC 15 Arcana or Religion). A party member who reaches the shadow before it disperses and succeeds on a DC 16 Persuasion check (addressed to Hades, not the character) can bargain for the character’s return. Hades will name a price. He is a god who honors contracts; the price will be real and fair and not pleasant. On a failed Charisma saving throw at death: the compact is discharged. The character dies as a mortal would, fully and without negotiation. The compact was the protection, and the protection is gone.

The shadow-curse manifestations available to you in the corruption divergence section above represent Hades asserting his claim while the character is still living. They are, in that sense, preparation. The character is being categorized, evaluated, and readied. The grove phrase is confirmation that the evaluation is ongoing and the result is not yet finalized. This is not comfort. It is context.