Linked portal squares warp pieces across the board.
How to play
Two pairs of linked portal squares (A1↔A2, B1↔B2) start in symmetric random spots, and after every move both pairs jump to new random empty squares. A piece that ends its move on a portal instantly warps to the twin square — capturing any enemy standing there — unless a friendly piece blocks the exit. Pieces may pass over portals freely. Your king is in check when an enemy piece could take it, directly or by warping onto it through a portal, and you may never leave your king in check (castling out of or through check is not allowed). Win by checkmate; no legal moves without check is stalemate, a draw. You play White.