Reversi is a free online board game you can play instantly in your browser against a computer opponent named Otto, no download, no account, and no waiting for another player. Play on the traditional 8x8 board starting from the standard four-disc opening: place your black disc so it outflanks a straight line of Otto's white discs between two of your own, and every outflanked disc flips to your color. If you have no legal move, your turn is skipped automatically. The match ends when the board fills or neither side can move, and whoever holds more discs wins. Play through 15 levels that make Otto stronger with every match, from loose corner giveaways early on to sharp corner control and mobility play near the final board. Win a level to unlock the next opponent strength; Try Again starts a fresh match at the same difficulty.
How to play Reversi
- The 8x8 board starts with two black and two white discs placed diagonally in the center.
- Tap any highlighted square to place your black disc so it forms a straight line — horizontal, vertical, or diagonal — trapping one or more of Otto's white discs between your new disc and another black disc.
- Every white disc trapped in that line flips to black immediately.
- If you have no legal move on your turn, it is skipped automatically and play passes to Otto.
- The match ends when the board is full or neither side has a legal move; whoever holds more discs at that point wins.
- Clear a level to unlock the next one, where Otto values corners and mobility more precisely and reads farther ahead.
Tips
- Corner squares can never be flipped once claimed — fight for them and avoid handing Otto an easy corner with a careless edge move.
- Having fewer discs in the middle game is often fine or even good: it limits Otto's outflanking options and keeps your position flexible.
- Avoid playing next to an empty corner — it usually gives Otto the square needed to flip in and claim that corner.
- Count your legal moves versus Otto's; having more available moves (mobility) matters more early on than simply holding more discs.
FAQ
Is Reversi free to play?
Yes. Reversi is completely free to play online with no download, no account, and no in-game purchases.
Does Reversi work on mobile?
Yes — tap any highlighted square to place a disc, so it works on phones, tablets, and desktop.
What is the difference between Reversi and Othello?
Reversi is the original 1880s public-domain game and the name used on this site. Othello is a later trademarked, standardized version of the same 8x8 outflanking rules — the gameplay here follows the same classic ruleset.
What happens if I have no legal move in Reversi?
Your turn is skipped automatically and play passes to Otto. If neither side has a legal move, the match ends immediately and discs are counted.
How many levels does Reversi have?
There are 15 levels. Otto starts with loose, corner-giving play on early levels, then values corners, mobility, and stable discs more precisely as you advance.