Reversi strategy: how to win at Reversi (plus the rules)

Reversi rules in one minute

Reversi is a two-player strategy game on an 8×8 board. One player has dark discs, the other light, and the goal is simple: have more discs of your colour on the board when the game ends. Here are the rules as they work in PlayTrova's Reversi:

1. The game starts with four discs in the centre, two dark and two light, placed diagonally. Dark always moves first.
2. On your turn, place a disc so that a straight line of your opponent's discs is trapped between your new disc and one of yours already on the board: across, up and down, or diagonally.
3. Every trapped disc flips to your colour. One move can flip lines in several directions at once.
4. If none of your moves would flip anything, you must pass. The game ends when neither player can move, usually when the board is full.
5. Whoever has more discs wins. Equal counts are a draw.

PlayTrova marks every square where you are allowed to play with a small dot, and a Pass button appears when you have no legal move.

The big secret: more discs now doesn't mean winning

Beginners try to flip as many discs as possible on every move. It feels great, but it usually backfires. Discs change colour all game long, so the count in the middle of the game means very little. What matters is mobility: how many good moves you have compared with your opponent.

Every disc you flip is a disc your opponent might flip back, and every one of your discs next to an empty square gives them somewhere to play. Big flips in the opening often hand your opponent lots of choices while leaving you with few.

Try this habit: compare your candidate moves by how many replies they leave your opponent. A move that flips one disc and leaves them three options is often better than one that flips five and leaves them eight. Squeeze hard enough and they will be forced onto bad squares, or have no move at all, which means they must pass and you move again.

Corners: the most valuable squares in Reversi

A disc in a corner can never be flipped. To flip a disc, it has to be trapped between two enemy discs in a line, and there is no square beyond a corner in any direction. Once you own a corner, it is yours for the rest of the game.

Corners also protect their neighbours. A row of your discs running along an edge from a corner you own is very hard to flip, and these safe discs (often called stable discs) pile up as the game goes on. Many games are decided by who wins more corners.

Edges come next. A disc on an edge can only be flipped along that edge, never from the middle of the board. But don't grab edge squares just because you can: the ones next to an empty corner can still let your opponent in.

The danger squares next to each corner

If corners are gold, the squares around an empty corner are traps. The worst one is the square diagonally next to the corner, often called the X-square. The two edge squares beside a corner, the C-squares, are risky too.

Here is why. Imagine the top-left corner is empty and you put a disc on the square diagonally next to it. Later your opponent gets a disc on the next square along that same diagonal. Now the corner is a legal move for them: their new corner disc and their disc further along trap yours, it flips, and the corner belongs to them for good.

• Avoid the X-square while the corner next to it is empty, unless you have checked that your opponent can't take the corner.
• Be careful with C-squares for the same reason, especially when there are gaps along that edge.
• Once you own a corner, the squares next to it become safe and useful, so fill them in.
• Lure your opponent in. When they only have a few moves left, they may be forced to play next to a corner and hand it to you.

Avoid walls and play quiet moves

A wall is a long line of your discs sitting next to empty squares. It looks strong, but every empty square beside it is a possible move for your opponent. Discs that touch empty squares are called frontier discs, and having lots of them usually means giving your opponent lots of options.

Instead, look for quiet moves: moves that flip only a disc or two, ideally discs that are already surrounded, without adding new discs next to empty squares. Quiet moves keep your options open while your opponent slowly runs out of safe squares.

Reversi endgame: count before you flip

Once the board is nearly full, Reversi turns into maths. Every disc counts, and the move that flips the most right now is often not the one that wins. Look a move or two ahead and count how many discs each line really ends with.

A useful rule of thumb is parity: try to be the player who makes the last move in each empty pocket of the board, because whoever plays last in a pocket gets the final flips there. Pockets with an odd number of empty squares are usually the ones to move into first.

PlayTrova's daily endgame puzzles are perfect practice. You are to move with 8 to 12 empty squares left, and only some moves force a win against Grandmaster Owl, who plays the endgame perfectly. You get three hints, and you can retry or skip any puzzle.

Common Reversi mistakes

• Flipping as many discs as possible early on, then running out of good moves.
• Playing diagonally next to an empty corner and giving it away.
• Taking an edge square just because it's there, without checking the corner beside it.
• Building long walls of discs that give your opponent lots of new moves.
• Forgetting to count in the endgame and trusting the move that flips the most.

Practise Reversi strategy online

PlayTrova has four computer characters to climb through, and you take turns being dark. Rookie Robo just loves flipping discs, which makes it a great opponent for practising corner traps. Clever Cat hunts corners, Sly Fox makes the most of every corner you give it, and Grandmaster Owl counts every disc of the endgame exactly. Against the computer you can also undo a move or ask for one of three hints per game.

You can also play a friend on the same device or send an invite link, free and with no sign-up. For more, browse board games and puzzle games.

Enjoy thinking ahead? Try Four in a Row with our Four in a Row strategy guide, or learn how to play checkers and practise in Checkers.

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