Chess

Introduction

The id for Chess is "chess". This is the name that is returned from the GET games request, and it used in all urls to replace the {game} parameter.

Game-specific requests

Armies

An army is a configuration for your half of the board.

• Get a list of your armies
• Change an army
• Create a new army
• Set as the current army (when you start matchmaking, the current army will be used?)

Environment

The environment lists all the pieces on the board.

{
    "board" : [
        ["", "", "", "", "", "", "", ""],
        ["", "", "", "", "", "", "", ""],
        ["", "", "", "", "", "", "", ""],
        ["", "", "", "", "", "", "", ""],
        ["", "", "", "", "", "", "", ""],
        ["", "", "", "", "", "", "", ""],
        ["", "", "", "", "", "", "", ""],
        ["", "", "", "", "", "", "", ""]
    ]
}

Each element of "board" corresponds to a row, such that when looking at the JSON representation, it looks as the board looks for the first player. Each element of a row is either an empty string indicating "no piece", or a string of the form "x,y" where x and y are integers. x denotes the player owning the piece, and y denotes the piece id.

Piece ids for the basic chess pieces are as follows:

• 0 Pawn
• 1 Rook
• 2 Knight
• 3 Bishop
• 4 Queen
• 5 King

The environment is always as above, there is no player-specific redaction.

Turn

The turn object should have at least values for "from" and "to". Each are coordinates (an array of a pair of values) corresponding to the locations on the board. Coordinates are specified with [0, 0] being in the bottom left. This is not the same as the coordinates used in the JSON array above.

{
    "from" : [0, 0],
    "to" : [0, 1]
}

Sometimes, additional information will be needed. Such as when promoting a pawn.

See the games page for details on making the request.

Events

Whenever a player makes a successful move, an event is fired of the form:

{
    "player" : 1,
    "from" : [0, 0],
"to" : [0, 1]
}

Rule differences

There are some rule differences from the original game.

• No 'en passant'. Because layout is arbitrary, there's no guarantee the pawns will be in play, or be in the positions required for this to work.
• No castling. Likewise.
• No checkmate. If you take the opponent's king, you win! This also means you are permitted to move into check.
• Promotion only to basic pieces. When the basic pawn promotes, you can pick any basic piece to promote to only.
• Repeated board state. No checks are done on board state. If the same board state is repeated, that's fine. Instead there is a turn limit of 50 turns after which a draw is declared. You can propose a draw earlier if you wish.