Composition and studies

The deliberate creation of a chess position or task designed to express an idea through a defined solution.

A deliberately constructed position that sets a precise task and has a solution intended by its composer.

The exact task a chess composition requires, together with any conditions needed to interpret that task.

A composition in which White must force a win or draw from a position created by the composer.

A problem in which White moves first and forces mate against every Black defense within the stated number of moves.

A directmate in which White must force checkmate in no more than two White moves.

A directmate in which White must force checkmate in no more than three White moves.

A directmate problem in which White must force mate in four or more White moves.

A problem in which Black and White cooperate so that White checkmates the black king in the stated number of moves.

A problem in which White forces a resisting Black to checkmate the white king.

A problem in which White forces Black to mate White and either side must mate immediately whenever possible.

A family of problems in which one side makes several consecutive moves while the other side remains stationary.

A composition in which White's first move creates no threat and every Black move permits a prepared White response.

A composition whose initial diagram contains at most seven units, counting kings, queens, rooks, bishops, knights, and pawns.

A composition whose initial diagram contains eight to twelve units, counting every king, queen, rook, bishop, knight, and pawn.

The correct first move that begins the actual solution of a problem, especially a directmate.

A nearly correct first move that fails to exactly one Black defense, called the refutation.

Virtual play already prepared in the initial position before the actual first move of the solution.

Thematic play contained in hypothetical possibilities of a composition even though it is not the line ultimately carried out.

The property that a chess composition has exactly its intended solution and no defect that invalidates it.

An unintended solution that begins with a different first move from the author's solution and makes the composition unsound.

A situation in which more than one continuation satisfies the composition's task after the first move.

The situation in which an identical chess composition already has an earlier priority date.

A compositional checkmate combining purity around the mated king with economical participation by the mating side's pieces.

A composition theme where two same-colored pieces mutually block one another by occupying the same intersection square in separate variations.

A composition theme where a White piece occupies the intersection of two Black defensive lines and forces interference between them.

A theme in which a sacrifice at two crossing defensive lines makes either capturing piece obstruct the other.

A theme in which one piece moves ahead along a row, column, or diagonal so a same-color piece can follow on that line.

A mechanism in which two Black pieces screen their king on one line and either one's departure prevents the other from moving away.

A theme in which a pawn starts on its original row, crosses the board, and promotes, meaning it becomes another piece.

A composition theme in which every Black promotion is answered by a White promotion to the same piece.

A theme in which several continuations appear possible, but after each defense exactly one works and the others are excluded.

A theme in which the same Black defenses receive White mating replies that rotate cyclically between two or more parts of the solution.

A theme in which the same two or more Black defenses receive different White mates across at least three phases of a problem.

Backward reasoning that deduces which earlier moves or events are compatible with the current position and legal chess play.

A legal sequence from the initial chess position to a given position, showing that the target position can be reached.

A convention that splits a solution into parts when permissions for certain special moves depend on incompatible legal histories.

Chess composition that introduces pieces, conditions, boards, or other rules that differ from orthodox chess.

A nonstandard chess piece that hurdles another piece on a row, column, or diagonal and lands exactly one square beyond it.

A nonstandard chess piece that repeats one or more knight steps in the same direction as a single move.

An added chess rule in which a captured piece is immediately reborn on a designated home square.

An added rule that normally requires Black to choose a legal move with the greatest straight-line distance from start to finish.