Game Rules
Undead Survival is not a heroic game. Every confrontation can be your last. Master these rules to maximize your chances of survival.
Introduction: The Basics
Before diving into the details of combat or infection, you need to understand one thing: this game is built around a single mechanic. Everything (attacks, mental resistance, infection checks) works the same way.
The D100 System
Roll a D100 (two ten-sided dice, one for the tens digit and one for the units digit). The goal is always to roll equal to or below your relevant skill score. The higher your skill, the better your chances. Critical results apply regardless of the skill being tested.
| Result | Effect |
|---|---|
| 01 - 05 | Critical Success: maximum damage + advantageous narrative effect. |
| ≤ Skill | Success: you hit your target. |
| > Skill | Normal Failure: your action fails without immediate catastrophe. |
| 95 - 100 | Critical Failure: your weapon jams, you fall, or you expose yourself. |
These results (success, critical success, failure, and critical failure) apply everywhere in the game: combat, SAN checks, infection rolls, Synchro tests. Learn them now and you will understand every rule that follows.
The Philosophy of Failure
Failing a roll in Undead Survival doesn't just mean "nothing happens". In a hostile environment, stress and tension always carry a cost:
- In Combat: You miss your shot or your opponent parries the attack. You manage to stay on your guard, but you wasted your action or spent precious ammunition for nothing.
- Out of Combat (Scavenging, Tech...): A normal failure usually means the action fails for now, or that valuable time is ticking away. The GM can decide that it is impossible to retry the exact same roll without a new tool or a drastic change in the situation.
Combat
Combat in Undead Survival is tense and lethal. Characters are survivors, not superheroes.
Initiative
Turn order is determined by your Agility (DEX) score. The higher your Agility, the faster you act.
- Calculation: Higher Agility = higher initiative.
- Firearm Bonus: If you already have a drawn and ready firearm, you gain +50 to your initiative for that turn.
- Tie: In case of a DEX tie, the character with the highest relevant combat skill (e.g. Firearms or Wrestling) goes first.
Turn Actions
During your turn, you may perform one major action. Here are the most common:
Melee attack, shoot, activate a Synchro capability.
Take cover, provide aid, observe (Intuition roll).
Draw/reload, open a door, flee combat.
Attack Resolution
Everything rests on the D100 roll.
When attacked in melee, you are not a passive target. You may choose:
- Dodge ～ You attempt to avoid the blow. If successful, you take no damage.
- Fight Back ～ You attempt to strike simultaneously. Both roll; whoever achieves the better success deals their damage.
Damage & Power
Damage depends on the weapon used (e.g. Knife 1D6+2), to which you add your Damage Bonus (Firearms or ranged weapons are not included).
| Power + Constitution | Damage Bonus (DB) | Build (Physical Impact) |
|---|---|---|
| ≤ 64 | −2 | −4 |
| 65 - 84 | −1 | −2 |
| 85 - 124 | 0 | 0 |
| 125 - 164 | +1D4 | 1 |
| 165 - 204 | +1D6 | 2 |
| 205+ | +2D6 | 3 |
Build measures the raw mass of a character relative to others.
If you roll exceptionally well (far below your skill), you deal maximum weapon damage + the normal dice roll. Often instant death for a minor Infected... or for you.
Common damage types
An attack's damage type (1D4, 2D4, 3D4...) determines which Wound Tier you risk reaching.
- Light damage (1D4) ～ 1 to 4 damage. You stay 100% within Light Wound (1-5): a small effect can't take down a character in one hit.
- Medium damage (2D4) ～ 2 to 8 damage. The minimum rises to 2 and the average roll lands around 5-6: the perfect pivot, starting to flirt with Serious Wound (6-11).
- Heavy damage (3D4) ～ 3 to 12 damage. The minimum rises to 3, guaranteeing a painful hit. A natural 12 can even reach the Major Wound threshold (12+), but only on an exceptional stroke of luck.
Health & Wounds
Hit Points (HP)
Your HP total (between 11 and 36) represents your overall endurance, luck, and resistance, not just raw flesh. You can bleed out slowly from a dozen small wounds without ever suffering a Major Wound. HP reaching 0 means you collapse from exhaustion, not necessarily from a single devastating blow.
Damage Tiers (Single Attack)
The severity of a wound is determined by the damage dealt in a single attack, not by your remaining HP. This makes every combat exchange meaningful, regardless of how much endurance you have left.
12+ damage in a single hit always triggers a Major Wound, whether you have 36 HP or 3 HP remaining. Resilience doesn't protect you from the violence of a bullet.
Sequelae (Major Wound ～ 12+ damage)
Any character taking 12+ damage from a single blow immediately suffers a Sequela based on the hit location, determined by the GM or a location roll.
Penalty to attacks and manual actions. Gripping a weapon, reloading, or climbing becomes significantly harder.
Movement reduced by half. Running, dodging, and chasing become dangerous gambles.
Minor persistent bleeding or penalty to physical exertion. Every sprint, every swing costs more than it should.
Stunned, lose your next minor action or suffer a concentration penalty. The world blurs for a moment too long.
A Major Wound does not knock you down as long as you still have HP. But the fight has fundamentally changed for you, every subsequent decision carries a new weight.
Out of Combat (0 HP)
Hit Points represent endurance, luck, and resistance, not just flesh. Reaching 0 HP means your body has nothing left to give, no matter how you got there.
You collapse from exhaustion. Unconscious and in need of immediate first aid, but your life is not at immediate risk with each passing second.
You are Dying. At the end of every round, make an Endurance roll (CON × 5). Fail once and it's over.
Weapon Lethality Index
To help you gauge the danger of each encounter, here is the damage range of the most common weapon categories and their probability of triggering a Major Wound.
| Weapon Category | Damage | Major Wound Risk |
|---|---|---|
| Unarmed / Fists | 1D4 |
Rarely reaches threshold |
| Melee (Knife, Bat, Machete) | 1D6+2 - 1D8+2 |
Possible on a good roll |
| Light Firearms (Pistol, Revolver) | 2D6 - 2D8 |
Regularly triggers |
| Heavy Weapons (Rifle, Shotgun) | 3D6 - 4D6 |
Almost always ～ extreme lethality |
A shotgun blast or rifle shot almost always crosses the 12-damage threshold. A critical success to the head can mean instant death. There are no expendable characters in this world, only bad decisions.
Fortune Points
You have a very limited reserve of Fortune Points. You may spend one to cancel a catastrophic action or stabilize your condition.
Once your Fortune Points are exhausted, you are alone against your fate. Use them wisely.
Infection & Mental
If bullets don't kill you, the infection will. Whatever is ravaging this world doesn't behave like any ordinary disease, and nobody truly understands why.
Struggle Phase
The infection is not a simple viral disease. It acts on the body in ways conventional medicine cannot explain or counter. In theory, once it takes hold, it is irreversible.
- Struggle Phase: Upon exposure (bite, fluid contact), you must make regular Endurance and Mental Strength (MS) rolls (every 3 turns if in combat).
- Degeneration: On a failed Constitution roll, your HP slowly and permanently decrease. Conventional medicine is ineffective against this systemic destruction.
- Alteration: On a failed Mental Strength roll, your lucidity crumbles, making Mental Health rolls harder.
Breaking Point & Transformation
When your HP drop to 10 or below, your body can no longer hold back what is eating away at you from within.
At each stressful event, the GM will call for a Synchronization roll. On a failure, you lose control. Your character transforms into an Infected and passes under the Game Master's control.
The Synchro Miracle
There is an infinitesimal chance that something shifts inside you instead of consuming you. If, at the critical threshold, you achieve a Critical Success (1 to 3%) on your Synchronization roll:
- Synchronization: Something in you reacts differently to the infection. Your body changes, but not like the others.
- Evolution: Roll a D1000 and obtain a random Unique Capability.
- Vegetative State (Forced Rest): Your body collapses to process the mutation. You remain unconscious and vulnerable for an extended period.
- Recovery: After this rest, you wake with full HP. You are no longer quite the same person, but you are alive.
A character in a vegetative state looks remarkably like an Infected in terminal phase. Will your allies choose to protect you... or end you out of fear?
Mental Health (SAN)
Mental Health represents your psychological resilience against the horrors of this world. It is directly tied to your Mental Strenght (MS): the stronger your mind, the more it can absorb before shattering.
MS × 5
At character creation, your current SAN equals your max SAN. Losses are flat values, a character with MF 15 has 75 SAN points to absorb before total breakdown.
| Remaining SAN % | Mental State |
|---|---|
| 80% ～ 100% | Stable |
| 60% ～ 79% | Worried |
| 40% ～ 59% | Disturbed |
| 20% ～ 39% | Unstable |
| 1% ～ 19% | Broken |
| 0% | Mental Breakdown |
| SAN Roll Result | SAN Loss |
|---|---|
| Success | 0 or 1 point |
| Failure | 1D10 or 1D20 |
- Crisis (Temporary Madness) ～ Triggered if you lose 5 or more SAN points at once. You momentarily lose control, panic, hallucinations, paralysis. The GM determines the nature and duration of the crisis.
- Trauma ～ Triggered if you lose 20% or more of your maximum SAN during a single game session. A Trauma leaves a lasting mark on the mind: a persistent fear, a compulsion, a memory that won't fade. It doesn't heal with a good night's sleep.
Your mind can no longer hold. The character is declared psychologically dead, Mental Breakdown is irreversible. They are no longer playable by their original owner.
Habituation & Recovery
A survivor's mind adapts. You don't remain indefinitely terrified by the same visions, but that adaptation comes at a cost, and rest is still the only real lifeline.
- Horror Habituation: After facing around ten standard Infected, you no longer lose SAN for that type of encounter. Special Infected, macabre staging, or traumatic revelations will still affect you, those never become routine.
- Recovering SAN (Rest & Relaxation): Mental health can recover through activities rooted in the character's past. A survivor who loved swimming might recover 1D4 SAN after an hour in a preserved pool. If it's a deep passion, the GM can grant up to 1D8 SAN. But remember: a Trauma doesn't heal with rest alone. It takes something more.
Synchronization & Capabilities
Synchronization (SP) represents something that awakened in you, a resonance between your body and this changed world. It is your fuel for altering reality or your own limits. With over 1,000 catalogued Capabilities, mastering Synchro can mean the difference between survival and transformation.
Capability Types
With more than 1,000 catalogued capabilities, they fall into three broad categories:
Once unlocked, always active and free. They may modify your physical appearance and/or grant you permanent bonuses.
Require voluntary activation and generally consume a fixed SP amount. Certain rare conditions can make this cost random.
Halfway between passive and active. They often act on their own but can consume SP unexpectedly depending on the situation.
Recovering Sync Points
- Rest: The primary means of regenerating Sync Points. A rested body and mind allow this resonance to stabilize naturally.
- GeneTech Supplements: Rumored special pills capable of boosting Synchro. Beware: side effects are not always documented.
- GM Role: The Game Master may adjust your SP based on narrative events or the environment, certain locations seem to amplify or suppress this resonance.
Equipment & Encumbrance
Weight is the survivor's enemy. Every extra kilo slows you down against the Infected. Know your limits.
Max Load
Your carrying capacity is calculated with the following formula. We use Load Units rather than fixed kg for more flexibility (some items may weigh 0.5 units).
((CON × 5 + STR × 5) / 2) + 10
We use Load Units rather than fixed kilograms for greater flexibility. Some items may weigh 0.5 units.
Encumbrance Penalties
Exceeding your limit is not impossible, but it is extremely risky.
| Excess above limit | Penalty (physical actions) |
|---|---|
| Any excess | −10% |
| +5 units above limit | −15% |
| +10 units above limit | −20% |
For every additional 5 units above the base excess, the penalty increases by −5%. At +10 units over your limit, even opening a door can become complicated under stress.
The Survivor's Legacy
Unplayable Status: Once your character is declared permanently unplayable, whether through Physical Death (0 HP), Infection (Total Infection), or Spirit Death (0 SAN), their fate takes a dramatic turn. Rather than seeing your character sheet disappear forever into the archives, you have the option to offer them one last legacy by donating your survivor to the NPC public library.
- The Survivor's Snapshot: Your character is then cloned and immortalized in the exact state they were in when healthy. Their raw stats, trained skills, and acquired capabilities are preserved, instantly removing the infection, mental trauma, or fatal injuries that took them.
- A Second Life in the Lore: He thus joins the ranks of the universe's characters as a template, sound in body and mind. The GM can bring him back in future sessions as a merchant, scout, or settlement inhabitant... giving your former survivor a chance to cross paths with your next characters!