How to play
Reversi.
Follow the line.
Watch the balance turn.
One new disc. A line with your colour at both ends. Everything between turns over.
Close the line to flip the disc between.
Put your colour at both ends.
Black moves first. A new disc at D3 puts White’s D4 between it and the Black disc already at D5. That unbroken straight line is a bracket.
Follow the line, then watch the same D4 disc turn over. Discs stay on their squares; only their colour changes.
Hollow disc: trial placement. Follow the line before the flip.
A hollow disc is a trial. A solid disc has been placed. The line shows the reason for a flip.
Empty is only the beginning.
Now it is White’s turn. Try the hollow F3: the very next square, E3, is empty. Its diagonal also fails: E4 and D5 are Black, then C6 is empty. Neither line reaches a White endpoint.
White has three legal moves: C3, E3 and C5. Each captures at least one Black disc. You cannot play on an occupied square, jump a gap or skip your own disc.
Rejected F3 trial. Both routes stop at an empty square.
Which White trial closes a bracket?
Choose an answer. Look for the existing endpoint.
Read the answer
Yes. E3 brackets the Black E4 against the existing White E5.
Dashed small rings mark legal choices. They check the rules; they do not rank the moves.
The same rule, in White.
Choose E3 as one legal example. It brackets Black’s E4 against the White disc already at E5. E4 turns White.
Next Black considers F3. Before scrolling on, look horizontally left and diagonally down-left. Which lines reach an existing Black disc?
Hollow disc: trial placement. Follow the line before the flip.
Black tries F3. How many discs will flip?
Choose an answer. Look for the existing endpoint.
Read the answer
Exactly. E3 is bracketed horizontally against D3; E4 diagonally against D5. Both lines start at F3.
E3 is an example, not a forced or proven best reply. The hollow F3 is the next trial.
One move. Every closed line.
From F3, E3 lies between the new disc and Black’s D3. Diagonally, E4 lies between F3 and Black’s D5. Both lines close.
Place one Black disc at F3 and flip BOTH captured discs. Check all eight straight directions: across, down, up and diagonally. Flips do not start chain reactions.
Hollow disc: trial placement. Follow the line before the flip.
Every capture must run straight from the newly placed disc. A line cannot bend.
More discs now isn’t a win.
Black has six discs and White has one, but this is only the opening. White can still play E2, C3 or C5. The winner is decided at the end.
Mobility means having legal choices. Corners are useful because a disc in a corner cannot be bracketed: there is no square beyond the board for the other endpoint. Keep an eye on who can reach them.
Corners and mobility guide your thinking. Neither guarantees a win, and the biggest early flip is not always the strongest choice.
No move? The turn passes.
Jump to a separate late-game example, reached by legal play. It is not a prediction of our opening. White chooses C7 and flips D7 against E7.
Now Black has no legal move. White still has B1. Black must pass, so White plays again. You cannot choose to pass when a legal move exists.
Separate late-game position: White’s C7 trial.
Black cannot move. White can play B1. What next?
Choose an answer. Look for the existing endpoint.
Read the answer
Yes. Black must pass. White still has B1, so the game continues with White again.
Our regular game handles forced passes automatically. One side being stuck does not end the game.
Both stop. Then count.
White places at B1, capturing six Black discs along two lines. Now neither colour has a legal move. Only now is this example over.
White has 48 discs, Black has 15, and A8 is still empty. White wins. More discs at the end wins; equal counts draw. Empty squares are not awarded to either player.
Hollow disc: trial placement. Follow the line before the flip.
A full board ends play, but it is not required. The test is whether EITHER player has a legal move.
Try four moves of your ownYour hands.
Four real moves.
A fresh position, four moves into another game. Play both colours for four more legal placements. No timer, no computer replies, no need to finish a match.
Practice lives only on this page. Your regular Reversi match, side and thinking level stay separate.
Black 3 · White 50 / 4 placements
Choose an empty square. We’ll preview its capture before you place.
Start this practice again? You can undo the reset.
How to try a move
Tap an empty square to preview it and its capture lines. Choose Apply this move to place. Tap another square to compare. A hollow disc is still only a preview.
Keyboard: Tab into the board. Arrows move; Home/End go to a row’s ends. Enter or Space previews a move. Escape cancels a preview. Tab leaves the board for Apply or the controls.
The suggested legal move is an example, not a best-play hint. Undo takes back one placement. The exercise ends after four placements.
Every flip
has a reason.
Find an empty square. Follow a straight line of opponents. Close it with a disc already yours. Take that rule into a real match whenever you’re ready.
Play Reversi Return to your practiceFree to play. No account needed. Your saved match resumes when local saving is available.
The quick rules.
- Black opens. Start with two discs of each colour in the middle of an 8 × 8 board, then alternate turns.
- Bracket to play. Place on an empty square with an uninterrupted line of one or more opposing discs between the new disc and an existing own disc. Check horizontal, vertical and diagonal directions.
- Flip every capture. All bracketed directions flip. No gaps, bending, skipping your own disc or chain reactions.
- Pass only when stuck. A player with no legal move must pass; a player with a legal move must play.
- Both stuck ends play. Count the discs actually on the board. More wins; equal counts draw. Empty squares may remain.
A few good questions.
Can I flip just one of two closed lines?
No. Every opponent disc bracketed directly by the placement must flip. The F3 example above shows one horizontal and one diagonal capture.
Can a flipped disc capture more discs?
No. Captures are checked from the newly placed disc, using the position before it is played. Turning a disc does not start another capture.
Are corners a guaranteed win?
No. An occupied corner cannot be flipped, which makes it useful, but you still need good choices elsewhere. Early disc count is not a reliable prediction of the final result.
How does the regular game work?
Choose Black or White and Gentle, Steady or Deep thinking. The opponent runs locally in a browser Worker; these are search-budget settings, not ratings. Undo turn takes back your last move and its computer replies. Restarting or changing side/level asks before replacing unfinished play.
Does this practice replace my match?
No. It stays in page memory and clears on reload. Following Play Reversi opens the regular game with its own saved progress and settings.