DC20 Combat Reference
A quick-access guide for running combat during Elorea sessions using DC20 Beta 0.10. This is meant to sit next to you at the table for fast lookup.
TURN STRUCTURE
Movement Phase:
- Move up to half your Speed for free
- Use 1 AP to Sprint: move your full Speed instead
Action Point Pool: 4 AP per turn (typical character)
Free Actions (don’t cost AP):
- Talk or communicate
- Drop items or loosen equipment
- Minor environmental interactions (open a door, look around, gesture)
ACTION POINT COSTS
| Action | Cost | Notes |
|---|---|---|
| Attack (Martial) | 2 AP | Rolling to hit with weapon |
| Cast Spell | 2 AP | Most spells; some may vary by spell |
| Help (give Help Die) | 1 AP | Ally adds your Help Die to their next roll |
| Off-Hand Attack | 1 AP | Second attack with off-hand weapon |
| Dodge | 1 AP | Add Agility to PD until start of next turn |
| Interact with Object | 1 AP | Pick up item, activate device, draw weapon |
| Use Item/Potion | 1 AP | Drink a potion, use an activated item |
| Disengage | 1 AP | Move without provoking Opportunity Attacks |
| Hide | 1 AP | Make Stealth check; if successful, invisible until you act |
| Ready Action | 1 AP | Set up an action to trigger on a condition |
Note: A character must use at least 1 AP per turn if they’re conscious. If they can’t, they’re either unconscious or in a special condition.
ATTACK RESOLUTION
Basic Formula:
- Attacker rolls: d20 + Attack Modifier vs target’s Defence (PD or MD)
- Attack Modifier: d20 + Combat Mastery + relevant stat (Might for martial, Intellect for spells, etc.)
Outcomes:
| Result | Effect |
|---|---|
| Miss by 5 or less | Partial Hit (Martial only): attacker deals half weapon damage |
| Hit | Full weapon damage |
| Heavy Hit (beat by 5+) | Full damage + bonus effect (extra condition, repositioned, disarmed, etc.) or add +d6 damage |
| Critical (natural 20 OR beat by 10+) | Maximum weapon damage + bonus effect, automatically occurs |
Defence Values:
- Physical Defence (PD) = 8 + Combat Mastery + Agility + Intelligence (or armour formula if using armour rules)
- Mystical Defence (MD) = 8 + Combat Mastery + Charisma + Intelligence
- Combat Mastery = ⌈Level ÷ 2⌉ (rounded up: Level 1-2 = 1, Level 3-4 = 2, Level 5-6 = 3, etc.)
STAMINA POINTS (SP)
What They Represent: Physical endurance and the ability to perform special techniques.
How Many: Varies by class. Martial classes typically start with 2 SP at Level 1.
How to Use:
- Spend SP to activate Maneuvers (special combat techniques)
- Some class abilities consume SP
Recovery:
- Recover on Short Rest (1 hour)
- Some abilities restore SP on other triggers (check class details)
- Not recovered on Long Rest by default (unless class says otherwise)
MANA & SPELLCASTING
Mana Points (MP): The resource magical casters spend to cast spells.
Mana Spend Limit per Casting: Combat Mastery (the limit, not the cost)
- Level 1-2 character: can spend up to 1 MP per spell cast
- Level 3-4 character: can spend up to 2 MP per spell cast
- etc.
Spell Costs: Determined by spell level and the spell description.
Example: A Level 3-4 character (Combat Mastery 2) can cast a spell that costs up to 2 MP. If they cast a spell that costs 3 MP, they cannot—the cost exceeds their limit.
Recovery:
- MP recovers on Long Rest (8 hours)
- Some abilities or items restore MP on other triggers
STAMINA (HEALTH)
Stamina Points (HP): How much damage a character can take before falling.
At 0 HP: Death’s Door
When a character reaches 0 HP, they are not dead—they are on Death’s Door.
Death Save (at the start of each turn on Death’s Door):
- Make a Death Save vs DC 10 using Might or Charisma (your choice)
- Success: Nothing happens this turn
- Failure: AP maximum permanently reduced by 1 (until healed above 0 HP)
- 3 failures OR AP maximum reaches 0: Death
Getting Healed:
- Healing above 0 HP immediately removes Death’s Door and resets failure count to 0
- AP maximum returns to normal
Example: A character on Death’s Door fails two Death Saves. Their max AP drops from 4 to 2. If they fail one more Death Save, they reach AP max 0 and die. If they get healed to 1+ HP before that, they survive and the AP limit resets.
DEFENCE & DAMAGE REDUCTION
Grit Points (GP): Temporary damage reduction resource.
How Many: Equal to Might modifier (minimum 1)
- Example: Might +2 = 2 Grit Points
How to Use:
- Spend 1 Grit Point to reduce incoming damage by 1d6
- Can spend multiple Grit Points on a single attack (reduce by 2d6, 3d6, etc.)
- Can be used reactively when you take damage
Recovery: On Short Rest
ADVANTAGE & DISADVANTAGE
Advantage (ADV):
- Roll d20 twice, use the higher result
Disadvantage (DisADV):
- Roll d20 twice, use the lower result
Stacking: ADV and DisADV don’t stack. If you have multiple sources, it cancels out:
- 1 ADV + 1 DisADV = roll normally
- 2 ADV + 1 DisADV = 1 ADV (roll twice, higher)
- 1 ADV + 2 DisADV = 1 DisADV (roll twice, lower)
OPPORTUNITY ATTACKS
When They Trigger:
- An enemy within your melee range moves away from you without using Disengage
What Happens:
- You can make 1 melee attack as a reaction (doesn’t cost your action on your next turn)
- Costs no AP; it’s free
How to Avoid:
- Use the Disengage action (1 AP) to move without provoking Opportunity Attacks
HELP DICE
Basic Mechanic:
- Spend 1 AP to Help an ally
- Ally adds your Help Die to their next d20 roll on their turn
Help Die Size (by Level):
| Level | Help Die |
|---|---|
| 1-4 | d4 |
| 5-8 | d6 |
| 9-12 | d8 |
| 13+ | d10 |
Multiple Helpers: If multiple characters Help the same ally, they only get one Help Die (usually the largest).
COMMON CONDITIONS & THEIR EFFECTS
| Condition | Effect |
|---|---|
| Slowed | Speed halved |
| Dazed | Lose 1 AP this turn |
| Impaired | DisADV on Attack rolls |
| Poisoned | DisADV on all checks |
| Frightened | Cannot willingly move toward fear source |
| Stunned | Cannot take actions; Speed 0 |
| Exposed | Attacks against you have ADV |
| Grappled | Speed 0; escape with Might or Agility vs grappler’s check |
| Prone | Melee attacks vs you have ADV; ranged attacks have DisADV |
| Blinded | DisADV on Attack rolls; attacks vs you have ADV |
| Invisible | ADV on your Attack rolls; attacks vs you have DisADV |
| Bloodied | Below half max HP; triggers some abilities |
QUICK NPC STAT BLOCKS
For quick reference on common enemy types:
Minion (Level 0):
- PD 10, MD 8
- HP 3-5
- Attacks: +2 to hit
- Damage: d6 or weapon
Soldier (Level 1):
- PD 12, MD 10
- HP 8-12
- Attacks: +3 to hit
- Damage: d8 or weapon
Champion (Level 3):
- PD 14, MD 12
- HP 20-30
- Attacks: +5 to hit
- Damage: d10 + bonus
Modify as needed for your encounter.
ROUND STRUCTURE (How Combat Actually Flows)
- Initiative: All combatants roll Initiative (d20 + Agility modifier). Highest goes first.
- Round: Each character takes a turn in Initiative order.
- On Your Turn: Spend your 4 AP. Move. Interact. Attack. Cast. Whatever you choose.
- Reactions: During other people’s turns, you can use reactions (free) if they trigger.
- End of Round: Check for ongoing effects, conditions that expire, etc.
- Repeat: Next round begins.
DM REMINDERS
- Let players narrate what they’re doing, then resolve mechanics
- Partial Hits on misses (for Martial attacks) keep combat dynamic
- Heavy Hits and Crits should feel special—describe the bonus effect dramatically
- Help Dice encourage teamwork; reward it
- Death’s Door is dramatic but fair—it takes 3 failures to die, and healing resets the clock
- Conditions are powerful; use them to vary combat tactics beyond just “roll to hit”