Combat System

Overview

The Combat System is a critical component of the Commander game engine, handling all aspects of creature combat including attacks, blocks, damage assignment, and combat-specific abilities. This system is especially complex in Commander due to the multiplayer nature of the format and the special rules regarding commander damage.

Core Components

The combat system consists of several interconnected components:

Combat Phase Management - Handling the flow through combat steps
Attack Declaration System - Managing which creatures attack and who they attack
Block Declaration System - Managing how defending players assign blockers
Damage Assignment System - Calculating and applying combat damage
Commander Damage Tracking - Monitoring and accumulating commander damage
Combat Triggers - Handling abilities that trigger during combat

System Architecture

The combat system uses a modular design pattern to separate concerns:

#![allow(unused)]
fn main() {
// Core combat system resource
#[derive(Resource)]
pub struct CombatSystem {
    pub active_combat_step: Option<CombatStep>,
    pub attackers: HashMap<Entity, AttackData>,
    pub blockers: HashMap<Entity, BlockData>,
    pub combat_triggers: Vec<CombatTrigger>,
    pub damage_assignment_order: Vec<Entity>,
    pub combat_history: VecDeque<CombatEvent>,
}

// Data for an attacking creature
#[derive(Debug, Clone)]
pub struct AttackData {
    pub attacker: Entity,
    pub defender: Entity, // Can be a player or planeswalker
    pub is_commander: bool,
    pub requirements: Vec<AttackRequirement>,
    pub restrictions: Vec<AttackRestriction>,
}

// Data for a blocking creature
#[derive(Debug, Clone)]
pub struct BlockData {
    pub blocker: Entity,
    pub blocked_attackers: Vec<Entity>,
    pub requirements: Vec<BlockRequirement>,
    pub restrictions: Vec<BlockRestriction>,
}

// Combat event for history tracking
#[derive(Debug, Clone)]
pub enum CombatEvent {
    BeginCombat { turn: u32, active_player: Entity },
    AttackDeclared { attacker: Entity, defender: Entity },
    BlockDeclared { blocker: Entity, attacker: Entity },
    DamageDealt { source: Entity, target: Entity, amount: u32, is_commander_damage: bool },
    CombatEnded { turn: u32 },
}
}

Integration with Other Systems

The combat system interfaces with several other game systems:

Turn Manager - For phase control and player ordering
Stack System - For handling combat-triggered abilities
Damage System - For applying damage and handling prevention/redirection effects
Game State System - For tracking changes to the game state during combat
Player System - For player state changes (life totals, commander damage)

Documentation Structure

This documentation is organized into several parts:

Combat Phases - Detailed implementation of each combat step
Commander Damage - Special handling of commander damage
Multiplayer Combat - Combat in a multiplayer environment
Combat Abilities - Implementation of combat-specific abilities
Combat Verification - Testing and verification approach