Reversi Strategy Guide: Master Othello with Proven Tactics

Corners are the most valuable squares on the board because they can never be flipped. Once you place a disc in a corner, it is permanently yours. This single principle shapes the entire strategy of Reversi. You should actively work to capture corners while preventing your opponent from reaching them. The safest way to take a corner is to wait until your opponent is forced to play adjacent to it, then capture it on your next turn. Be careful not to play in the squares directly adjacent to corners (called "X-squares" and "C-squares") unless you are certain your opponent cannot take the corner. Giving away a corner is often the single biggest mistake in a game.

Edges (the squares along the border) are the second most stable positions after corners. Discs on the edge can only be flipped along the edge itself, making them relatively safe. Controlling edges gives you a strategic advantage and limits your opponent's options. However, not all edge positions are equal. A solid edge with your color from corner to corner is excellent. An edge with gaps can be exploited by your opponent to flip segments. Disc minimization is a counterintuitive but powerful concept. In the early and mid-game, having fewer discs is often better because you have more mobility (more valid moves). Your opponent with many discs has fewer options and may be forced into bad moves.

Mobility - the number of valid moves available to you - is the most important strategic concept in Reversi after corners. The player with more options controls the game. If your opponent runs out of moves, they must pass, giving you consecutive turns. To maintain high mobility, keep your discs flexible and avoid filling the board early. Play moves that maximize your future options while restricting your opponent's. Think of it as controlling the pace and direction of the game. A common beginner mistake is maximizing disc count early. Flipping many discs feels rewarding but often reduces your mobility in subsequent turns. Focus on move quality over quantity.

The endgame begins when the board starts filling up, usually around the last 15-20 moves. This is when disc count starts to matter. Every remaining empty square becomes a potential point, and the player who controls the final moves often wins. In the endgame, count the remaining squares and calculate who will get the most. Look for sequences of moves that cascade - one move flips several discs and opens up another strong move. Planning two or three moves ahead in the endgame is essential. If you are behind in disc count entering the endgame, focus on swamping - making moves that flip the maximum number of opponent discs. If you are ahead, play conservatively to protect your lead and run out the clock.