Long-range pieces slide extra squares after long moves.
How to play
Standard chess, except bishops, rooks and queens carry momentum: a non-capturing move of 3 or 4 squares slides 1 extra square in the same direction, and a move of 5+ squares slides 2 extra, stopping early at the first piece or board edge. Your move must not leave your king in check after the slide. Win by checkmate; stalemate, 50-move rule and bare kings draw. Pawns promote to queen.