Chess problems

A chess problem, also called a chess composition, is a puzzle created by the composer using chess pieces on a chessboard, which presents the solver with a particular task. For instance, a position may be given with the instruction that White is to move first, and checkmate Black in two moves against any possible defence. A chess problem fundamentally differs from over-the-board play in that the latter involves a struggle between Black and White, whereas the former involves a competition between the composer and the solver. Most positions which occur in a chess problem are unrealistic in the sense that they are very unlikely to occur in over-the-board play. There is a substantial amount of specialized jargon used in connection with chess problems.