⚔️ Player Reference
Combat Quick Reference — Warhammer 40k / D&D 5e One-Shot
Pure 5e RAW — only the flavor is heresy. Mechanics are untouched. Keep this in front of you during every engagement.
1. Starting Combat — Initiative
When violence breaks out, everyone rolls initiative (including the GM for each enemy group):
- Roll 1d20 + your DEX modifier.
- The GM announces the order highest → lowest. Ties: PC beats NPC; tied PCs decide among themselves.
- The order stays fixed for the entire combat — it only resets when the DM calls a new initiative.
"First contact protocols. Roll for priority engagement order."
2. Structure of a Round
One round = ~6 seconds. Every combatant gets one turn per round, in initiative order.
On Your Turn You Have:
| Resource | Quantity | Key Rule |
|---|---|---|
| Action | 1 | Attack, cast a spell, dash, etc. (see §3) |
| Bonus Action | 1 | Only if a feature/spell specifically grants one — not free |
| Movement | Up to your speed | Can split it around your action (move, attack, move) |
| Free Actions | As needed | Speak a few words, drop an item, release a grapple |
| Object Interaction | 1 free / turn | Draw/stow a weapon, open a door, pull a lever — a second one costs your Action |
Off Your Turn You Have:
| Resource | Quantity | Key Rule |
|---|---|---|
| Reaction | 1 (resets each round at the start of your turn) | Opportunity attacks, readied actions, certain spells/powers |
3. Actions — The Standard Menu
| Action | What It Does |
|---|---|
| Attack | Make one melee or ranged attack (more with Extra Attack) |
| Cast a Spell / Use Psychic Power | Per the power's casting time |
| Dash | Your movement doubles this turn |
| Disengage | Your movement this turn does not provoke opportunity attacks |
| Dodge | Attacks against you have disadvantage; you have advantage on DEX saves — until your next turn |
| Help | Give one ally advantage on their next ability check or attack roll vs. a creature within 5 ft of you |
| Hide | Make a Stealth (DEX) check to become unseen — must have somewhere to hide |
| Ready | Declare an action + trigger ("When the cultist rounds the corner, I shoot"); resolve it as a Reaction when the trigger fires |
| Search | Make a Perception (WIS) or Investigation (INT) check to find something |
| Grapple | As part of the Attack action (replaces one attack): your Athletics (STR) vs. their Athletics or Acrobatics (their choice). Success = Grappled (speed 0) |
| Shove | As part of the Attack action (replaces one attack): same contest as grapple. Success = knock Prone OR push 5 ft |
| Use an Object | When interacting with an item requires your full attention |
Opportunity Attack (Reaction): When an enemy you can see voluntarily leaves your reach, you may make one melee attack against them as a Reaction — no action required.
4. Attack Rolls & Damage
Making an Attack
- Roll 1d20 + your attack bonus (STR or DEX modifier + Proficiency Bonus if proficient).
- Compare the result to the target's Armor Class (AC).
- Equal to or beat the AC = hit. Under the AC = miss.
On a Hit
Roll your weapon's damage dice + the relevant modifier (usually the same STR or DEX used to attack; firearms/ranged use DEX unless a feature says otherwise).
| Roll | Result |
|---|---|
| Natural 1 (before any modifiers) | Automatic miss — no matter how high your bonus |
| Natural 20 (before any modifiers) | Critical Hit — see §5 |
Ranged Attacks in Melee
If a hostile creature is within 5 ft of you, ranged attack rolls (lasguns, bolt pistols, etc.) have disadvantage.
Two-Weapon Fighting
If you hold a Light weapon in each hand and Attack with the main hand, you may use your Bonus Action to make one attack with the off-hand weapon — but do not add your ability modifier to the off-hand damage (unless a class feature says so).
5. Critical Hits
On a natural 20, the attack hits regardless of AC and deals a critical hit:
- Roll all of the weapon's damage dice twice, then add modifiers once.
- Example: Chainsword normally deals 1d8 + 3 slashing → on a crit roll 2d8 + 3.
"The Emperor's own luck guides your blade through the gap in its corrupted armor."
6. Advantage & Disadvantage
| State | How to Roll |
|---|---|
| Advantage | Roll 2d20, take the higher result |
| Disadvantage | Roll 2d20, take the lower result |
Critical rule — they don't stack. No matter how many sources grant advantage or impose disadvantage, you still roll exactly 2d20. If you have both advantage AND disadvantage simultaneously, they cancel out and you roll a single d20 as normal.
7. Cover
Physical terrain provides AC and Dex save bonuses while a creature is behind it:
| Cover | AC Bonus | DEX Save Bonus | Notes |
|---|---|---|---|
| Half Cover | +2 | +2 | Low wall, barricade, large creature between you |
| Three-Quarters Cover | +5 | +5 | Gun emplacement, narrow firing slit, large pillar |
| Total Cover | Cannot be targeted directly | — | Fully hidden; area effects may still reach you |
Use the rubble. Guardsmen who don't use cover don't stay Guardsmen long.
8. Conditions
These are the most common status effects you'll encounter. Each lasts until its specific removal condition is met (end of turn, saving throw, breaking a grapple, etc.).
| Condition | Effect |
|---|---|
| Blinded | Can't see. Attacks against a Blinded target have advantage; a Blinded attacker has disadvantage on attacks |
| Charmed | Cannot attack the charmer. The charmer has advantage on social ability checks against the charmed creature |
| Deafened | Can't hear. Automatically fails any ability check requiring hearing |
| Frightened | Disadvantage on all attack rolls and ability checks while the source of fear is in sight. Cannot willingly move closer to the source |
| Grappled | Speed becomes 0. Ends if the grappler is incapacitated, or if an effect moves the grappled creature out of reach |
| Incapacitated | Cannot take Actions or Reactions |
| Invisible | Cannot be seen. Attacks against an Invisible creature have disadvantage; its attacks have advantage. It still occupies space and makes noise |
| Paralyzed | Incapacitated, cannot move or speak. Auto-fails STR and DEX saves. Attacks against it have advantage and hits within 5 ft are automatic critical hits |
| Poisoned | Disadvantage on attack rolls and ability checks |
| Prone | Can only crawl (costs 1 ft of movement per 1 ft traveled). Disadvantage on attacks. Melee attacks against a Prone creature have advantage; ranged attacks have disadvantage. Stand up costs half your movement speed |
| Restrained | Speed becomes 0. Attacks against it have advantage; its attacks have disadvantage. Disadvantage on DEX saves |
| Stunned | Incapacitated, cannot move, can only speak falteringly. Auto-fails STR and DEX saves. Attacks against it have advantage |
| Unconscious | Incapacitated, prone, drops everything held. Auto-fails STR and DEX saves. Attacks have advantage; hits within 5 ft are automatic critical hits |
9. Death — The Emperor Decides
Dropping to 0 HP
- You fall Unconscious and are dying.
- On each of your turns at 0 HP, you make a Death Saving Throw (a d20, no modifiers):
- 10 or higher = 1 success
- 9 or lower = 1 failure
- Natural 20 = regain 1 HP (you regain consciousness immediately)
- Natural 1 = 2 failures
- 3 successes = Stable (unconscious but no longer dying; HP stays at 0)
- 3 failures = Dead (the Emperor has judged you wanting)
Taking Damage at 0 HP
- Any damage while at 0 HP = 1 automatic failure
- A critical hit while at 0 HP = 2 automatic failures
Recovery
Any healing (medi-pack, stimm injector, psychic power, Acts of Faith) of at least 1 HP brings an unconscious creature back to consciousness immediately with that many HP.
A stable creature (3 successes, 0 HP) that isn't healed regains 1 HP after 1d4 hours.
Successes and failures don't carry over between combats — reset when the fight ends.
10. Healing
| Source | Effect |
|---|---|
| Medi-Pack / Stimm Injector (Healing Potion) | Drink (Action) or administer to an adjacent creature (Action): 2d4 + 2 HP |
| Greater Medi-Kit (Greater Healing Potion) | 4d4 + 4 HP |
| Spending Hit Dice (Short Rest) | 1+ hours rest: spend any number of Hit Dice, rolling each and adding your CON modifier per die |
| Long Rest | 8+ hours: regain all HP and at least half your total Hit Dice (round up) |
| Stabilize (First Aid) | Action + touch: DC 10 Medicine (WIS) check to stabilize a dying creature at 0 HP (stops death saves; they're stable but still unconscious at 0 HP) |
In 40k, there's no shame in the Medicae — a dead soldier helps nobody. Keep your people up.
11. Concentration
Some psychic powers and abilities require Concentration to maintain:
- You can concentrate on only one effect at a time. Starting a new concentration spell immediately ends the previous one.
- Taking damage while concentrating requires a CON saving throw to maintain it: DC 10 or half the damage dealt, whichever is higher.
- Being Incapacitated or killed ends concentration instantly.
12. Ability Checks — DC Reference
| Difficulty | DC |
|---|---|
| Very Easy | 5 |
| Easy | 10 |
| Medium | 15 ← default when unsure |
| Hard | 20 |
| Very Hard | 25 |
| Nearly Impossible | 30 |
Proficiency Bonus by level: 1-4 = +2 · 5-8 = +3 · 9-12 = +4 · 13-16 = +5 · 17-20 = +6
13. Combat Priority — Playing Smart
- Understand the action economy. You have an Action, Bonus Action (if applicable), and Movement every turn. Don't waste them — even a "free" Dash keeps pressure on.
- Use cover every time it's available. +2 or +5 AC can be the difference between alive and at 0 HP.
- Focus fire. A dead enemy takes no turns. Two enemies at half HP still both take full turns.
- Prone + melee = brutal. If you can knock something Prone and stay adjacent, your melee attacks have advantage and your ranged allies have disadvantage — but that usually still favors your side.
- Disengage vs. Opportunity Attack. If you need to run, Disengage is an Action. If you think the enemy will miss you, just move and accept the risk.
- Help your ally over a mediocre attack. If your own attack is likely to miss but you can Help, giving your ally advantage on a strong attack is often better action economy.
- Dying ally = stabilize or heal, not avenge. Three failures comes fast. Spend your Action on Medicine or a medi-pack before you think about revenge.
"The Imperium does not mourn its dead — but it cannot afford to lose the living. Stay effective."
Rules: D&D 5e RAW (SRD). Flavor: Warhammer 40,000, Games Workshop.