Castling-960

Castling-960 is what trips up even experienced players. Memorize the key point: wherever the king and rook start, after castling they land on the classical squares. Kingside — king on g1, rook on f1; queenside — king on c1, rook on d1. The starting squares mean nothing, the final squares mean everything. The conditions are the usual ones: neither the king nor the rook has moved, the path is clear, and the king doesn't pass through attacked squares.

There's exactly one gesture in the app: drag the king straight ONTO your rook. Not "two squares sideways" like you're used to in classical chess — onto the rook. That removes all the confusion: you've shown which rook you're castling with — the system does the rest. Learn the gesture now so you don't waste a single second on it in a game.