chooseCombatDamageAssignment

Sent when an attacker’s combat damage must be divided among its blockers — and possibly the defending player or planeswalker if the attacker has trample. For example, a 4/4 trampler blocked by a 2/2 may assign 2 to the blocker and let the remaining 2 trample through.

Answered on the board

The reference client answers this prompt through interaction with the battlefield (not a modal dialog), so it has no standalone screenshot. The fields below are what the engine sends; the response is what the client returns once the player has acted.

Arguments

input.type is "chooseCombatDamageAssignment". The remaining fields:

TypeScript

interface ChooseCombatDamageAssignmentInput {
  attackerId: string;
  blockerIds: Array<string>;
  defenderId?: string;
  totalDamage: number;
  attackerHasDeathtouch: boolean;
}

Rust

#[serde(rename_all = "camelCase")]
pub struct ChooseCombatDamageAssignmentInput {
    pub attacker_id: String,
    pub blocker_ids: Vec<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub defender_id: Option<String>,
    pub total_damage: i32,
    pub attacker_has_deathtouch: bool,
}

Response

type ChooseCombatDamageAssignmentOutput = {
  type: "combatDamageAssignmentDecision";
  assignments: CombatDamageAssignmentEntry[];
};
type CombatDamageAssignmentEntry = { assigneeId: string; damage: number };

Return one entry per assignee (each blocker, and defenderId if damage tramples through). The damage values must sum to totalDamage. With attackerHasDeathtouch, a single point of damage counts as lethal, so as little as 1 may be assigned to a blocker before moving on.

Example

{
  "promptId": 13,
  "decidingPlayerId": "player-0",
  "input": {
    "type": "chooseCombatDamageAssignment",
    "attackerId": "bf-3",
    "blockerIds": ["bf-7"],
    "defenderId": "player-1",
    "totalDamage": 4,
    "attackerHasDeathtouch": false
  }
}

{
  "promptId": 13,
  "output": {
    "type": "combatDamageAssignmentDecision",
    "assignments": [
      { "assigneeId": "bf-7", "damage": 2 },
      { "assigneeId": "player-1", "damage": 2 }
    ]
  }
}