Ladder mate

Ladder mate is not merely a final position. It is a method for pushing the king to an edge. Two rooks, or a rook and queen, build parallel walls. One limits the king's space while the other checks from the next line.

How the ladder advances

1. One rook cuts off a row or column and confines the king to part of the board.
2. The other rook checks from a parallel line and forces the king backward.
3. The rooks alternate those roles until the king reaches the edge and cannot retreat any farther.

Before every check, the attacker must make sure the king cannot capture the advancing piece. The rooks may protect each other, remain safely separated, or switch sides when the king approaches. Unlike king and rook checkmate, the classic ladder uses two rooks, or a rook and queen, and does not require the attacking king to form the main barrier.