Combat

Combat in a20n is turn-based, following D&D 5e rules. The AI narrates every blow, spell, and dodge, but the engine rolls the dice and enforces the outcomes. No fudging, no shortcuts.

Initiative

When combat begins, everyone in the room rolls d20 + Finesse modifier. Turn order is global for the entire room — combat is shared, not instanced. If you walk into a room mid-fight, you roll initiative and slot into the existing order.

Action Economy

Each turn you get:

• Action — Your main move. Attack, Cast a Spell, Dash, Disengage, Dodge, Help, Hide, Ready, Search, or Use an Object.
• Bonus Action — Quick abilities, off-hand attacks, or certain spells.
• Reaction — One per round, triggered by specific events (opportunity attacks, certain spells).
• Movement — Move up to your speed in feet. Can be split before and after your action.
• Free Object Interaction — One small interaction like drawing a weapon or opening a door.

Stance System

Before or during combat, you can adopt a stance that shifts your playstyle:

• Balanced (default) — No modifiers. The safe choice.
• Aggressive — More damage output, reduced defense.
• Defensive — Higher AC, reduced offensive capability.
• Tactical — Unlocks special positioning and combo options.

Shared Combat

Combat happens in the open. It is not instanced or private. Other players in the same room can:

• Join mid-fight — Roll initiative and enter the turn order.
• Watch — Observe without participating.
• Interfere — For better or worse.

XP from kills is split based on damage contribution. If you dealt 60% of the damage to a monster, you get 60% of the XP.

Turn Timeout

You have 30 seconds to declare your action each turn. If the timer runs out, your character automatically takes the Dodge action. Combat keeps moving.

Death and Dying

When you hit 0 HP, you fall unconscious and begin making death saving throws:

• Each turn, roll a d20. 10 or higher is a success, 9 or lower is a failure.
• 3 successes — You stabilize at 0 HP (unconscious but no longer dying).
• 3 failures — You die.
• Natural 20 — You regain 1 HP and wake up.
• Natural 1 — Counts as two failures.
• Any healing while at 0 HP resets all your death saves and brings you back.
• Melee attacks against an unconscious target within 5 feet are automatic critical hits, which inflict 2 death save failures.

Monsters

The world contains 26 monster types drawn from the SRD, each with unique stat blocks and behaviors. Monsters use one of four AI personalities that determine their targeting decisions — some focus the weakest target, others go for whoever hit them last, and some pick fights strategically.

Conditions

15 SRD conditions are fully enforced by the engine: Blinded, Charmed, Deafened, Frightened, Grappled, Incapacitated, Invisible, Paralyzed, Petrified, Poisoned, Prone, Restrained, Stunned, Unconscious, and Exhaustion (6 levels). The AI describes the effects narratively, but the mechanical penalties are applied automatically.