Othello / Reversi on an 8×8 board. You are Black and move first.

• Place a disc so it sandwiches one or more opponent discs in a straight line (8 directions).
• All sandwiched discs flip to your color.
• If you cannot move, you pass. Game ends when neither can move.
• Most discs wins. Easy: hints + unlimited undo. Medium: 3 undos. Hard: no undo.
• Tap or click a highlighted square to move.