Goal: trap the rival king. Gold is the light court and always moves first; Emerald is the dark court.
Tap: tap one of your figures, then a glowing square. Tap it again to let go.
Castling: tap the king, then two squares toward a rook. The path must be clear and neither the king's square nor the crossed square may be attacked.
En passant: a pawn may take a rival pawn that has just dashed two squares past it. The chance vanishes after one move.
Promotion: a pawn reaching the far rank becomes a queen, rook, bishop or knight — choose the guise.
Draws: stalemate, fifty moves without a capture or pawn move, or too little material to force mate.
Spells: pawns and royalty cast beams, bishops and rooks hurl arcing magic, and knights charge as spectral horses. A capture burns, breaks or explodes the rival figure and leaves a scar on the square for the rest of the duel.
Endgame: when seventeen figures have fallen, the board splits with a great crack. A checkmated king topples and bursts into flame — no panel, just the ruin.
Local duel: two players share this screen. Multiplayer: open the lobby with a friend; the host is Gold, the guest Emerald, and the board turns for Emerald.