Last updated: March 2026
What Is Reversi?
Reversi is a classic two-player strategy board game played on an 8x8 grid with black and white discs. Also known as Othello, the game was first popularized in the late 1800s and became a worldwide phenomenon when Mattel trademarked the Othello version in 1971. The rules are famously simple — place discs to outflank your opponent and flip their pieces to your color — but the strategy runs remarkably deep.
What makes Reversi endlessly compelling is the dramatic swings in board control. A single well-placed disc in a corner can flip an entire diagonal, turning a losing position into a winning one in seconds. The game rewards patience and positional thinking over raw aggression — players who grab too many discs early often find themselves cornered and overwhelmed in the endgame.
Our free online version features three AI difficulty levels, smooth disc flip animations, real-time score tracking, and persistent statistics saved to your browser. It works perfectly on desktop and mobile, with no download or signup required.
How to Play Reversi
Place your disc on any empty square that outflanks one or more of your opponent's discs. Outflanking means your new disc and an existing disc of your color form a straight line (horizontal, vertical, or diagonal) with only opponent discs between them. All outflanked discs are flipped to your color.
Legal moves are highlighted on the board with semi-transparent indicators, so you can always see your options. If you have no legal moves, your turn is automatically passed. The game ends when neither player can move or the board is full.
Control the corners — they are the most valuable squares on the board because corner discs can never be flipped. Avoid the squares directly adjacent to empty corners, as placing discs there gives your opponent easy access to the corner. In the early game, focus on mobility (keeping your options open) rather than maximizing your disc count.
The player with more discs when the game ends wins. Choose from Easy, Medium, or Hard AI, and track your stats over time to see your improvement.
Key Features
Three AI difficulty levels provide a challenge for every skill level. Easy mode picks random moves, perfect for learning. Medium mode plays greedily with corner and edge preference. Hard mode uses minimax with alpha-beta pruning, searching 5-8 moves ahead with a sophisticated evaluation function that weighs corner control, edge stability, mobility, and disc count.
Smooth disc flip animations bring every move to life. When you outflank opponent discs, they flip one by one with a satisfying 3D rotation effect. Legal moves are clearly highlighted, and the score bar updates in real time so you always know the state of the game.
Persistent statistics track your games played, win/loss/draw record, win rate per difficulty, best score, and win streaks. All data is stored locally in your browser — nothing is sent to a server, and there is no signup required.
Frequently Asked Questions
What is the difference between Reversi and Othello?
Reversi and Othello are essentially the same game with identical rules. Othello is a trademarked version of Reversi, popularized by Mattel in the 1970s with the tagline "A minute to learn, a lifetime to master." Both use an 8x8 board with black and white discs, and the goal is to have more discs of your color when the board is full. Our game plays by standard Othello rules: the board starts with 4 discs in the center, Black moves first, and you flip opponent discs by outflanking them in any direction.
What are the best opening strategies for Reversi?
The most important strategy in Reversi is to control the corners, since corner discs can never be flipped. Avoid placing discs on squares directly adjacent to empty corners, as this gives your opponent easy access to the corner. In the early game, try to have fewer discs than your opponent (this is called the "mobility" strategy) — having fewer discs means you have more legal moves available, giving you more flexibility. Focus on limiting your opponent's moves while keeping yours open.
How does the AI difficulty work?
Easy mode picks a random legal move each turn, great for beginners learning the rules. Medium mode uses a greedy strategy that maximizes disc flips and prefers corners and edges. Hard mode uses a minimax algorithm with alpha-beta pruning, searching 5-8 moves ahead. The Hard AI evaluates positions based on corner control, edge stability, mobility (number of available moves), and disc count, making it a genuinely challenging opponent.
How do I flip discs in Reversi?
To flip discs, place your disc on an empty square so that one or more of your opponent's discs are in a straight line between your new disc and another disc of your color. This works in all 8 directions: horizontal, vertical, and diagonal. All opponent discs caught between your new disc and an existing disc of your color in any of these directions are flipped to your color in a single move. You must flip at least one disc to make a legal move.
What happens when I can't make a move?
If you have no legal moves available on your turn, your turn is automatically passed to your opponent. The game only ends when neither player can make a legal move, or when the board is completely full. The player with more discs of their color on the board wins. If both players have the same number of discs, the game is a draw.
Are my game stats saved?
Yes. Your games played, wins, losses, draws, win rate per difficulty, best score, and current win streak are all saved in your browser's local storage. Stats persist across sessions but are specific to your browser and device — they are never sent to a server.
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