Reversi

How to play Reversi

Reversi is a two-player game on an 8 by 8 board, with discs that are black on one side and white on the other. It plays exactly like Othello, which is a trademarked brand of the same game.

• The start: four discs sit in the middle, two of each color, crossed diagonally. Black moves first.
• Every move must flip. Place a disc so that it traps one or more of your opponent's discs in a straight line (across, up and down, or diagonally) between the new disc and another of yours. All the trapped discs turn over to your color.
• One move can flip in several directions at once. Every line the new disc closes is flipped.
• No move, no turn. If you can't flip anything, you pass and your opponent moves again. You can't pass while you have a legal move.
• The game ends when neither player can move, usually when the board is full. The player with more discs wins.

Playing on Poozee

• vs Computer: choose to play Black (you move first) or White. Easy leans toward whatever move flips the most discs, so a beginner can beat it. Medium looks two moves ahead and knows corners are valuable. Hard looks four moves ahead and plays the last 10 moves perfectly. Expert thinks for up to a second a move.
• 2 Players: share one screen and take turns. The scoreboard keeps count for Black and White.
• To move, tap or click a square with a dot. The dots show every legal move; turn them off with the Show legal moves switch if you want to find moves yourself.
• Hint (against the computer) marks the move the Expert computer would play for you. Undo takes back your last move, along with the computer's reply, as many times as you like.
• Passes happen by themselves: when a player has no legal move, the game says so and the other player goes again.
• Your game is saved in this browser, so you can close the tab and pick it up later. Your record is kept separately for each level.

Strategy basics

1. Take the corners. A disc in a corner can never be flipped, and it anchors the edges next to it.
2. Stay off the squares next to an empty corner. The X-squares (diagonally inside a corner) and C-squares (on the edge beside it) are how corners get given away.
3. Fewer discs early is fine. What counts in the middle of the game is how many moves you have. Grabbing lots of discs usually hands your opponent more moves and fewer for you.
4. Keep your discs inside. Discs that touch empty squares give your opponent something to flip. Quiet moves that flip a disc or two in the middle are often the strongest.

Our Reversi and Othello strategy guide tests each of these tips with thousands of computer games and walks through positions checked by an exact endgame search.

Where the game comes from

In a paper posted in October 2023, "Othello is Solved", Hiroki Takizawa announced a computer proof that on the standard 8 by 8 board, perfect play by both players leads to a draw. Poozee's Reversi is our own version of the classic game and isn't affiliated with the Othello brand.