The game is a turn based on two-player game, and each player is represented by a set of pieces, being black or white, 16 pieces in all:

The game is played on a chessboard, consisting of 64 squares: eight rows (1-8) and eight columns (a-h). The squares are alternately light (white) and dark (black). Players take turns in moving one piece at a time. White player always starts the game (the player that plays with the white pieces). A move consists of moving one of the pieces of the player to a different square, following the rules of movement for that piece - there is one special exception, named castling, where players move two pieces simultaneously.

A player can take a piece of the opponent by moving one of his own pieces to the square that contains a piece of the opponent. The opponent's piece is then removed from the board, and is out of play for the rest of the game. Beware that taking is not compulsory!

The board is set up in the following way: At the second row there are eight white pawns, at the seventh row there are eight black pawns. At the first row, from left to right, we have a: rook, knight, bishop, queen, king, bishop, knight, and rook. Note that the queens start on squares of their own color, with a dark square in each player's left hand corner.

To make a move, the player must drag a piece to another square. Once the player has picked up the piece, a marker piece will appear below legal squares this piece is being dragged over. If the piece is dropped on an illegal square it is being snapped back to the square it originally came from. All piece types have different movement patterns, which are the following:

The king moves one square in any direction, horizontally, vertically, or diagonally. There is one special type of move, made by a king and rook simultaneously, called castling: see below.The king is the most important piece of the game, and moves must be made in such a way that the king is never in check: see below.

The queen has the combined moves of the rook and the bishop, i.e., the queen may move in any straight line, horizontal, vertical, or diagonal.

The bishop moves in a straight diagonal line. The bishop may also not jump over other pieces.

The knight makes a move that consists of first one step in a horizontal or vertical direction, and then one step diagonally in an outward direction. The knight jumps: it is allowed that the first square that the knight passes over is occupied by an arbitrary piece. For instance, white can start the game by moving his knight from b1 to c3. The knight does further not affect the piece that is jumped over. As usual, a knight takes a piece of the opponent by moving to the square that contains that piece.

The rook moves in a straight line, horizontally or vertically. The rook may not jump over other pieces, that is: all squares between the square where the rook starts its move and where the rook ends its move must be empty. (As for all pieces, when the square where the rook ends his move contains a piece of the opponent, then this piece is taken. The square where the rook ends his move may not contain a piece of the player owning this rook.)

The pawn moves differently regarding whether it moves to an empty square or whether it takes a piece of the opponent. When a pawn does not take, it moves one square straight forward. When this pawn has not moved at all, i.e., the pawn is still at the second row (from the owning players view), the pawn may make a double step straight forward. For instance, a white pawn on d2 can be moved to d4. When taking, the pawn goes one square diagonally forward. There is one special rule, called taking en-passant. When a pawn makes a double step from the second row to the fourth row, and there is an enemy pawn on an adjacent square on the fourth row, then this enemy pawn in the next move may move diagonally to the square that was passed over by the double-stepping pawn, which is on the third row.

In this same move, the double-stepping pawn is taken. This taking en-passant must be done directly: if the player who could take en-passant does not do this in the first move after the double step, this pawn cannot be taken anymore by an en-passant move. This special rule can be optionally enabled or disabled in the settings dialog of the matchmaking lobby (it is enabled by default). Pawns that reach the last row of the board are promoted. When a player moves a pawn to the last row of the board, he replaces the pawn with a queen, rook, knight, or bishop (of the same color). Usually, players will promote the pawn to a queen, but the other types of pieces are also allowed. It is not required that the pawn is promoted to a piece that was taken earlier. Thus, it is for instance possible that a player has at a certain moment two or more queens.