cxd4

Cxd4 is a chess move notation that indicates a pawn from the c-file captures a piece or pawn on the square d4 and lands there. In algebraic notation, pawns are identified only by their originating file and the fact that a capture occurred, followed by the destination square. Therefore, cxd4 means a pawn on the c-file moves diagonally to d4, capturing whatever was on that square.

Ambiguity and origin. In most positions, cxd4 uniquely identifies a capture by a c-file pawn. If two pawns from the c-file could theoretically capture on the same square, the notation would reflect the actual origin file; however, such ambiguity rarely occurs, and cxd4 is typically clear. If the capturing pawn were from a different file, the notation would use that file letter, for example exd4 or bxd4.

Examples. White can play cxd4 if White has a pawn on c3 and Black has a piece or pawn on d4. The pawn from c3 moves to d4, capturing on that square. In a common opening line, Black’s c-pawn can capture on d4: 1.e4 c5 2.d4 cxd4, where Black’s pawn from c5 captures the pawn on d4 and ends on d4.

Purpose and consequences. A move like cxd4 often helps contest the center, open lines for other pieces, or simplify the position. It can alter pawn structure, influence control of the d-file, and affect piece activity, such as freeing lines for queens or bishops or creating targets for response.

Relation to other notation. The analogous pawn captures include exd4, bxc3, and similar. For non-pawn captures, the moving piece is indicated with its letter (Nxd4, Bxd4, etc.).