A piece with a light-blue glow is guarded by a friendly knight and can also leap like a knight (for moving or capturing), on top of its usual move. Knights themselves can never capture or be captured.
Invented by Mannis Charosh in 1972. The rules are ordinary chess, except that any piece guarded by a friendly knight (other than the king or a knight itself) can also move or capture like a knight, in addition to its usual move. Knights can move but never capture and can never be captured — they only ever land on empty squares. A pawn cannot reach the 1st or 8th rank via a relayed knight leap (no back-door promotion). Pawns retain their double-step option whenever they sit on their own starting rank.
Simplifications: en passant and castling are omitted. Check and checkmate aren't enforced — capturing the king directly ends the game (a knight itself can never threaten the king, consistent with the rule that it cannot capture at all).