chooseBlockers

Sent during the declare-blockers step of combat. The engine tells the client which attackers may be blocked, which of the defender’s creatures can block, and any constraints — for example, an attacker with menace that must be blocked by two or more creatures, or a creature that must be blocked if able.

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 "chooseBlockers". The remaining fields:

TypeScript

interface ChooseBlockersInput {
  attackers: Array<BlockableAttackerDto>;
  availableBlockerIds: Array<string>;
  error?: string;
}

Rust

#[serde(rename_all = "camelCase")]
pub struct ChooseBlockersInput {
    pub attackers: Vec<BlockableAttackerDto>,
    pub available_blocker_ids: Vec<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub error: Option<String>,
}

References: BlockableAttackerDto

Response

type ChooseBlockersOutput = { type: "declareBlockers"; assignments: BlockAssignment[] };
type BlockAssignment = { blockerId: string; attackerId: string };

Return one BlockAssignment for each blocking creature, naming the attacker it blocks. A single blocker may block one attacker; to gang-block, return multiple assignments that share the same attackerId. Creatures left back are omitted.

Example

{
  "promptId": 9,
  "decidingPlayerId": "player-1",
  "input": {
    "type": "chooseBlockers",
    "attackers": [
      {
        "attackerId": "bf-3",
        "validBlockerIds": ["bf-7", "bf-8"],
        "minBlockers": 1,
        "mustBeBlocked": false
      },
      {
        "attackerId": "bf-4",
        "validBlockerIds": ["bf-7", "bf-8"],
        "minBlockers": 2,
        "mustBeBlocked": false
      }
    ],
    "availableBlockerIds": ["bf-7", "bf-8"]
  }
}

{
  "promptId": 9,
  "output": {
    "type": "declareBlockers",
    "assignments": [{ "blockerId": "bf-7", "attackerId": "bf-3" }]
  }
}