Blindfold chess

In blindfold chess, one or both players play without seeing the board position. The pieces move by the same rules as in an ordinary game. Each blindfolded player must remember where every piece is and update that mental picture after every move.

Moves are commonly communicated aloud using algebraic notation, a system that identifies pieces and squares with letters and numbers. The player hears the opponent's move, updates the position in memory, calculates a reply, and announces it. In an exhibition, another person or an interface may make the physical moves.

Blindfold chess can be a single game or part of a blindfold simultaneous exhibition, where one player keeps several different positions in mind at once. The essential rules of ordinary chess do not change; what changes is the visual information available to the player who is playing blindfold.