Reversi (Othello)

Reversi, also widely known as Othello, is a strategic board game played on an 8x8 grid where two players compete to control the most squares with their colored discs. Each move must outflank one or more of the opponent's discs by placing your disc so that a straight line (horizontal, vertical, or diagonal) of opponent discs is enclosed between your new disc and another of your existing discs. All outflanked discs are then flipped to your color. The game was invented in the 1880s and was later trademarked as Othello in 1971 in Japan with the tagline 'a minute to learn, a lifetime to master.' Reversi has become one of the most respected abstract strategy games, with active competitive communities and annual world championships.

1. The game starts with four discs in the center of the 8x8 board, two of each color placed diagonally.
2. Black moves first. You must place a disc adjacent to an opponent's disc such that at least one line of opponent discs is outflanked.
3. Outflanked means your new disc and an existing disc of your color enclose a straight line of opponent discs with no gaps.
4. All outflanked opponent discs (in all directions) are flipped to your color in a single move.
5. If you cannot make a valid move, your turn is skipped and your opponent plays again.
6. The game ends when neither player can move or the board is full. The player with the most discs wins.

• Every move must outflank at least one opponent disc
• All outflanked discs in all directions are flipped in one move
• If no valid move exists, the turn passes to the opponent
• The game ends when neither player can move or the board is full
• The player with the most discs on the board at the end wins
• A disc can outflank in up to eight directions simultaneously

• Prioritize corners. Corner discs can never be flipped and provide permanent control. They are the most valuable squares on the board.
• Avoid the squares immediately adjacent to empty corners (called X-squares and C-squares). Playing there gives your opponent access to the corner.
• Minimize your disc count in the early game. Having fewer discs means your opponent has fewer places to play, limiting their options.
• Control the edges. Discs on the edge can only be outflanked from one direction, making them relatively stable.
• Think about mobility. The player with more available moves has more flexibility and control over the game.
• In the endgame, maximize your disc count. The strategy shifts from mobility and positioning to flipping as many discs as possible.

• Standard Reversi (Othello): The classic 8x8 version with the standard starting position. The most widely played competitive format.
• 6x6 Reversi: A smaller board for quicker games. Good for learning strategy basics before playing on the full 8x8 board.
• Anti-Reversi: The goal is reversed. The player with the fewest discs at the end wins. Requires completely different strategic thinking.

• Dramatic momentum swings where the board flips in your favor
• Easy to learn with deeply layered strategic depth
• Quick games that typically last 10 to 20 minutes
• The satisfaction of executing a corner capture strategy
• A truly balanced game where every move creates opportunities and risks

Play Reversi for free against our computer opponent. Features legal move highlighting, disc flip animations, and real-time score tracking. Multiple difficulty levels available. No download needed. Works on all devices.

Reversi is a masterpiece of abstract strategy. The simple rule of outflanking creates a game of profound depth where the entire board can change in a single move. Whether you are a beginner learning corners or an expert perfecting mobility play, every game offers a new challenge. Place your first disc now.