Reversi
Trap a line of your rival between two of yours and the discs turn over.
- Players
- 2
- Length
- ~15 min
- Genre
- Abstract strategy
Reversi dates from 1883 and has one rule: place a disc so that a line of your rival sits between it and one of yours, and that whole line turns over.
Lines run across, down and diagonally, and a single move can turn several at once. The board changes in stripes rather than one disc at a time, which is why a position in the middlegame says almost nothing about how it ends.
A move is legal only if it turns something over. That has a consequence people rarely expect: sometimes there is nowhere to play at all, and the turn simply goes back.
How to play
- 1Create a room and send a friend the link or the six-character code.
- 2Four discs start in the middle, two of each colour, set on a diagonal.
- 3Dark opens. The squares you may play are highlighted in your colour.
- 4Place a disc so it traps a line of your rival between it and one of yours — the line turns over.
- 5If you have nowhere to play, the turn passes automatically.
- 6The match ends when neither colour can play. Most discs wins.
Highlights
- The classic 8x8 board and the classic opening position
- Legal moves are highlighted, so the rule is visible rather than guessed
- Turns pass automatically when there is nowhere to play
- Turn timer, configurable when the room is created
- Perfect information: nothing to peek at, it is all on the board
Tactics and tips
- Corners can never be turned over. One corner is worth more than a dozen discs in the middle.
- Do not take the squares beside a corner early — they are what lets your rival reach the corner itself.
- Holding fewer discs in the middlegame is usually good: less to be trapped, and more places you can still play.
- Count moves, not discs. The match is won by leaving your rival with nowhere to go.
- Edges are safer than the middle: a disc on an edge can only be turned along that edge.
Common mistakes
- Celebrating a big lead in the middlegame, which one move into a corner can undo.
- Turning over as many discs as possible every move, and paying for it in freedom to manoeuvre.
- Taking the square diagonally beside a corner and handing over the corner next turn.
- Assuming the board has to fill up. Matches often end with squares to spare.
Frequently asked questions
How many players do I need?
Two, one colour each. The game has no variant for more.
Why can I not play on every empty square?
A move is legal only if it turns at least one disc over. A run that reaches the edge of the board, or that has a gap in it, traps nothing.
What happens if I have nowhere to play?
Your turn passes automatically. If neither colour can play, the match is over — even with empty squares left.
How does this differ from the game with the similar name?
It is the same game. The mechanic is from 1883 and free to use; the better-known title is a registered trademark, so this one goes by its original name.
Do I need to install anything?
No. It runs in the browser on desktop and mobile, and an account is optional.