Othello (Reversi)

Should you start with the daily puzzle or a full game?

Choose Impossible Comeback to practice endgame decisions. You play Black from a position the publisher presents as winnable despite White’s lead. A full game starts with two discs of each color in the middle and lets you practice the opening, middle game and endgame in order.^[1][2][4]

New players can start a full game against the computer and use the legal move markers to learn how capture lines work. We played d3 from the standard opening against Easy. It flipped one disc and produced a 4–1 lead. The computer replied c5, flipped one disc and brought the board back to 3–3. In the two-player mode we tried the same opening move and the game paused for White to act.^[2][3]

Choose two players on one device if a friend is beside you, or an online game if you want separate screens. Choose the daily once you can read capture lines and want a more constrained board.^[3]

Captured by Daily Games from the original game

How to make a legal Othello move

Place one disc on an empty square. It must trap at least one uninterrupted line of the other color between the new disc and one of your existing discs. Captures can go horizontally, vertically or diagonally. Every trapped line from your placement flips, so one move can change several parts of the board.^[4]

Black starts a standard game. If a player has no legal move, their turn passes. A legal move is compulsory when one exists, and the game ends when neither side can move. Count the discs on the board to find the winner.^[4]

What the six-disc flip showed in our daily test

On Impossible Comeback #46, we started behind 14–38, selected Hint once, and tried b7, a square labeled as a legal move that flips six discs.

The board flipped six discs and placed a seventh black disc at b7. The count became 21–32. After evaluation, the game reported that the win had slipped on move one and offered Try again.

The net change makes sense: Black adds the new disc and gains six converted discs, while White loses those six. The legal-move label and score panel therefore answer two separate questions, namely whether the move is allowed and what it changes right now.^[1][4]

Captured by Daily Games from the original game

How to compare two legal moves in a Reversi endgame

The score panel describes the board you have now. To evaluate a move, picture where White can land immediately afterward, then estimate which player gets the last move in each pocket of empty squares. The World Othello Federation’s endgame lesson gives worked examples of the value of move order.^[4][5]

What should you check before taking the biggest flip?

Compare a large flip with a smaller move by checking the moves you leave for White. Pay particular attention to newly available corners. A corner that has been occupied can never flip, and a reply that takes it can alter adjacent edge play for the rest of the game. Use the daily hint if you have narrowed the position to a few candidate squares and still cannot see the difference.^[1][4][5]

Why the online game is also called Reversi

Othello is the trademarked name used by the licensed game and the World Othello Federation. The browser publisher uses Reversi for its 8×8 disc-flipping game. The game linked here is the independent reversi.site edition and Impossible Comeback is that site’s daily challenge.^[7][4][3]