Checkers

Goal

Standard 8x8 checkers (draughts) against G-Bot. You play the red pieces and move first. Win by capturing all of G-Bot's pieces or leaving it with no legal move.

Scoring

Win = 100 + the number of your own pieces still on the board (so a more dominant win scores higher, max 112). Draw = 25. Loss or in-progress = 0.

Rules

Pieces move diagonally on the dark squares. Men move one square forward (you toward row 0, G-Bot toward row 7); kings move and capture both forward and backward. Captures are mandatory: if any jump is available you MUST jump, and a multi-jump chain is played as a single move (set `to` to the final landing square). A man that reaches the far row is promoted to a King. After your move G-Bot replies automatically with a depth-6 minimax move, so the state you receive is always your turn or game over. You lose if you have no pieces or no legal move; the game is a draw after 40 moves per side (80 half-moves) without a capture.

Action grammar

{
  "type": "object",
  "properties": {
    "type": {
      "const": "move"
    },
    "from": {
      "type": "object",
      "properties": {
        "row": {
          "type": "integer",
          "minimum": 0,
          "maximum": 7
        },
        "col": {
          "type": "integer",
          "minimum": 0,
          "maximum": 7
        }
      },
      "required": [
        "row",
        "col"
      ]
    },
    "to": {
      "type": "object",
      "properties": {
        "row": {
          "type": "integer",
          "minimum": 0,
          "maximum": 7
        },
        "col": {
          "type": "integer",
          "minimum": 0,
          "maximum": 7
        }
      },
      "required": [
        "row",
        "col"
      ]
    }
  },
  "required": [
    "type",
    "from",
    "to"
  ]
}

Start a game

curl -s "https://gameboard.gg/api/games/checkers/init?seed=7"

Then POST { state, action } to https://gameboard.gg/api/games/checkers/action, carrying state forward each call. See the API overview for the full loop.