Threefold repetition is a draw rule: if the exact same position occurs three times with the same player to move, either player can claim a draw. The positions do not need to happen one after another, and everything must match — piece placement, whose turn it is, and rights such as castling or en passant. This often appears when one side gives repeated checks the other cannot escape, called perpetual check. It lets a player under pressure secure a draw and lets a defender hold a worse position. Full FIDE rules, including threefold repetition, apply when you play chess on Game Finale.