Two players, a board of 8 × 8 squares and flipping pieces that show ebony on one side and mother-of-pearl on the other. Trap an opponent’s piece between two of your own and it flips to your colour. At the end, whoever has more pieces of their colour on the board wins.
You can play on your own against the computer (three strengths) or with someone from the arcade. A game takes six to ten minutes — exactly 60 moves and a fixed end.
Four pieces sit crosswise in the middle: ebony on d5 and e4, mother-of-pearl on d4 and e5. Ebony moves first — whoever has the first move plays ebony. On your own you choose who starts; with two players the server draws lots.
You place a piece on an empty square. If, in one direction — across, down or diagonally — there is an unbroken line of your opponent’s pieces with one of your own behind it, that line is trapped. Every piece in it flips.
⭐ All eight directions count at once, so one move can flip lines upwards, sideways and diagonally together.
⚠️ A gap breaks the line, and flipping stops at the first of your own pieces.
A move is only legal where it traps at least one piece. So that you never have to search, legal squares always glow as small copper dots.
With “🔢 Show flip count” each dot shows how many pieces the move would flip. Experienced players may find that too much help — the switch remembers your choice.
If you have no legal move, you must pass. You do not have to do anything: the game notices, tells you, and your opponent moves again. The same works the other way round — then it is your turn twice in a row.
The game ends when neither player can move — usually because the board is full, sometimes earlier. Then the pieces are counted: more pieces of your colour wins, equal numbers are a draw. Empty squares are not given to anyone.
Anyone left without a single piece has, of course, lost.
⭐ Lots of pieces in the middle of the game are often a bad sign. Flipping a lot early gives your opponent many options — and takes away your own.
One tap is enough: tap a glowing square — the piece is down and the trapped pieces flip one after another. Tapping any other square tells you why nothing happens there. A slip never costs you your move.
The last piece placed carries a copper ring. Above the board a bar in ebony and mother-of-pearl shows who has how many pieces.
| Level | What it does |
|---|---|
| Easy | greedily takes the move that flips the most pieces |
| Medium | looks four half-moves ahead and knows what corners are worth |
| Hard | calculates for about half a second — and the last twelve moves exactly to the end |
“Easy” falls into exactly the trap described above. Games against the computer are practice: they appear in your record but earn neither points nor milestones.
What counts are games against other players: 10 points for a win, 4 for a draw, 1 for taking part — towards the arcade leaderboards (week, month, year).
Your level ⭐ is the number of milestones reached plus one. They are the same five as in the other Duel Corner games: your first game and first win against another player, playing 3 different people, 5 and 25 wins against other players.
Results and your settings are saved at the end of every game. A solo game in progress is not saved. In a duel the position lives on the server — you can carry on from another device.
Solo play runs entirely on your device. Once you have opened Reversi online, it also starts without a connection.
Tap “two players” above the board and you open a table straight away. While it is open nothing is set up — not even the starting cross — and an empty seat says “🪑 free”. The game only starts once both of you are there. Everything else (table code, invitations, call-back, move clock, chat) is in the 🎯 Duel Corner guide.