Perpetual check is a draw where one player keeps checking the other player’s King. There’s no intermediate moves, no breathing room, no free time to bring back pieces to defence. In chess discussions it is often abbreviated to just being called a “perpetual”.
It is a draw, although there’s actually no official rule called “perpetual check”. In practice, the game is usually drawn by agreement, or if there’s no agreement, then a draw can be claimed by either “triple repetition” or by “no progress” or by adjudication.
The most common types of perpetual check are where a Queen is checking a castled King in the corner, and the King can only move back and forth. The Queen just moves one square at a time, checking. These causes triple repetition.
There are also some common perpetual checks against castled Kings where the Queen swings back and forward on a diagonal. These types also quickly cause triple repetition draws.
Sometimes there are perpetual checks where the King doesn’t move, but another piece has to keep blocking the check each time.
Finally, sometimes there are perpetual checks where the King is running all around the board, being chased by the enemy Queen with never-ending checks. This type of perpetual check is sometimes called “infinite pursuit”. Queen endgames are well-known for this type of checking, and that is why they tend to be drawish.
Related Chess Tactics
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