How to play Reversi

1 player vs computer, or 2 online

Finish with more discs of your colour on the board than your opponent, on an eight-by-eight board where every move turns some of theirs into yours.

The rules, step by step

1. 1

   The game opens with four discs in the middle, two of each colour, sitting on the two diagonals. Dark plays first.

2. 2

   A move must trap at least one unbroken line of your opponent's discs between the disc you are placing and another of your own. The line may run in any of the eight directions.

3. 3

   Every disc you trapped flips to your colour, in every direction at once. A move that traps nothing is not a legal move.

4. 4

   The squares where you can legally play are ringed on the board. Tap one to play it.

5. 5

   If you have no legal move at all, your turn is skipped and your opponent plays again. That is a rule, not a fault.

6. 6

   The game ends when neither player can move. Whoever has more discs wins, and an equal count is a draw.

Three tips that change how you play

• Take corners, and give up nothing to get them. A corner disc can never be trapped, because there is no square on the far side of it. It is yours for the rest of the game, and it anchors two whole edges.
• Stay off the three squares next to a corner until the corner is settled. Playing one of them is the commonest way to hand a corner over, and the computer will take it every time.
• Count moves, not discs. Having more discs in the middle of a game is usually bad: it gives your opponent more places to play and you fewer. A player with one legal move has to make it, however terrible it is.

Why the square beside the corner loses

Suppose the top-left corner is empty and you play the square diagonally in from it, row two and column two. That square is now yours, and it is the only square that can bracket the corner for your opponent. On their next move they play the corner itself, trapping your disc between the corner and whatever they hold further down the diagonal. Now they own a corner that can never be flipped, and every disc they place along the top edge or the left edge anchors back to it. Discs you took twenty moves ago start turning over in blocks. That exchange, one square gained against one corner given, decides more games of Reversi than any other pattern on the board, and avoiding it is most of what separates a beginner from a competent player.

Three mistakes that cost beginners the game

Taking the move that flips the most discs.

The greedy move is almost always the wrong one before the endgame. Flipping a lot of discs puts your colour on the outside of the cluster, where it is easy to flip back, and it opens squares for your opponent. Aim to hold few discs and many options until the board is nearly full.

Playing a square next to an empty corner.

The three squares beside a corner exist to give the corner away, and the diagonal one is the worst square on the board. Leave them alone. If you are forced onto one, take an edge square rather than the diagonal.

Assuming a big lead in the middle of the game means anything.

It usually means the opposite. Reversi scores the final position and nothing before it, and a single corner late on can flip an entire edge and more. Do not count discs until neither player can move.

Common questions about Reversi