How to play reversi
- Black starts in the centre. The 8×8 board begins with two black and two white discs crossed in the middle. Black moves first.
- Sandwich to flip. Place a disc so that one or more of your opponent’s discs sit in a straight line between your new disc and another of yours — those discs flip to your colour.
- No move? Skip. If you have no legal placement, your turn is skipped. When neither side can move (or the board is full), the player with more discs wins.
- 2 player or vs CPU. Pass one device, or challenge Easy / Normal as Black or White. Legal squares are dotted so you never guess.
Strategy: corners, edges, mobility
- Take corners when you can. They never flip and anchor stable edges.
- Avoid the X/C squares early. Squares beside an empty corner often gift that corner away.
- Mobility beats disc count mid-game. Fewer discs but more legal moves usually means you control the endgame.
How strong is the computer?
Across 30 seeded games of Normal vs Easy, Normal won 30 — 15 as Black and 15 as White — by about 26 discs on average, over roughly 60 placements.
More two-player games
Also try four in a row, gomoku and dots and boxes. Full list: two-player games. Chinese: 黑白棋在线双人.