Othello is the version with a fixed starting position (four discs on the center diagonal) and is a registered trademark, which is why this game is called Reversi. In the original Reversi the board starts empty and each player places their first two discs on the central squares, with no captures. Here you can choose the standard or the free opening in settings.
Reversi
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Reversi
Outflank your opponent and flip the board in your favor
The classic duel of discs that change color
Reversi is a two-player strategy game on an 8x8 board, with black discs on one side and white on the other. On each turn you place a disc on an empty square so that it outflanks, in a straight line (horizontal, vertical or diagonal), one or more opposing discs between the new disc and another of yours. Every outflanked disc flips to your color, in all directions at once. If you have no move that flips discs, you pass, and the game ends when neither player can move, usually with a full board. Whoever has more discs of their own color wins. This game uses the standard Othello starting position (discs on the center diagonal, Black moves first) and offers the original Reversi free opening as an option, where the first four moves go on the central squares. Against the computer there are four levels: beginner, intermediate, hard and master. The AI uses minimax search with alpha-beta pruning, scoring corners, mobility, frontier discs and stable edges, and solves the endgame by brute force. The search runs in a separate worker, so the screen never freezes while the computer thinks. There are hints, undo and a move history using a-h columns and 1-8 rows.
Tap a marked square to play
- Pick the mode and level. Black moves first, and dots on the board show where you can play.
- Tap a marked square (or use the arrow keys and Enter) to place your disc and flip the outflanked ones.
- If someone has no move, the turn passes by itself. The player with more discs when nobody can move wins. Use Hint or Undo whenever you need.
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