Reversi Strategy for Beginners

Level 1: the first 60 seconds before you play

1. It is an 8×8 board with four center discs, and Black moves first. White starts on d4 and e5; Black starts on e4 and d5. After that, place one new disc on an empty square. Existing discs never move to another square.
2. A legal move must flip at least one disc. Along a row, column, or diagonal, the chosen square must bracket opposing discs between your new disc and another disc of your color. The bracketed discs flip immediately.
3. Pass when no legal move exists. If no dotted square appears on your turn, you must give the turn to your opponent. You cannot pass while the board offers a legal move.
4. The final disc count decides the winner. When neither side can move, count the black and white discs. The higher count wins; empty squares do not score.

Those four facts are enough to begin. Ignore frontier discs and parity in your first game. Do only two things: play on a dotted square, and check all four corners before every move. If the bracket is still unclear, use the illustrated first move. To try immediately, open Play vs AI.

Level 2: stop impulsive moves with four questions

1. Can I take a secure corner? A corner has only three neighboring directions and is very difficult to flip once held. If a corner is a legal move, examine it first.
2. Does this move use an X-square or C-square beside an empty corner? The diagonal X-square and the edge-adjacent C-squares often give the corner to your opponent while it remains empty.
3. Which new legal moves does my opponent receive? Count them, but also inspect their locations. A move that opens several edge or corner choices may be poor even if it flips many discs.
4. Is there a quieter legal move? If neither candidate gives away a corner, compare which flips fewer discs, exposes fewer frontier discs, and preserves more choices for your next turn.

Take a secure corner; be patient beside an empty one

A corner is the most stable square on the board. It has only three adjacent directions, so once you occupy it, your opponent can rarely flip it. The nearby squares are dangerous while the corner is empty. The diagonal square is the X-square—b2 beside an empty a1. The edge neighbours are C-squares—a2 and b1 beside a1. Playing there often gives your opponent the corner on the next move. Once the corner is occupied, those same squares become much safer.

Level 3: count legal moves before discs in the midgame

The midgame disc count is deceptive. You may flip a large region and appear comfortably ahead while your opponent has seven dotted legal squares and you have only two. They can choose among safer moves while you may soon be forced into danger. When comparing candidates, count each side’s legal moves after the move, then note whether those moves approach a corner. Being a few discs behind is often acceptable if you keep control of the choices.

More mobility is not automatically better. Six legal moves beside empty corners may be worse than two safe moves. The count tells you who has more freedom; the locations tell you whether that freedom is useful.

Level 4: discs beside empty squares feed your opponent’s next turn

A frontier disc is adjacent to at least one empty square. Because frontier discs sit beside future playing space, they are more likely to become part of an opponent’s bracket. A large midgame flip often creates many frontier discs of your color and gives the opponent more ways to play around the outside. This is a common reason why “flipping more” can leave you with fewer useful moves.

You do not need an exact frontier count on every turn. Compare two candidate moves instead. Which one spreads your color along more empty squares? Which keeps your discs tucked inside and opens fewer legal moves for your opponent? The quieter move is often the one worth calculating first.

Level 5: when few squares remain, count parity by region

Disc count finally becomes important in the endgame, but move order matters just as much. Treat connected empty squares as a region. If both sides can only alternate moves within that region, the player who takes its final square often controls the last major flips. Whether a region contains an odd or even number of empty squares affects who is likely to play there last.

Endgame parity is not a rule that “odd always wins.” Passes, multiple empty regions, and brackets crossing between regions can change the order. Begin simply: when about ten empty squares remain, pause, group connected empties, and estimate how many moves each region contains. During replay, check whether entering one region too early handed its final move to your opponent.

Turn one AI game into deliberate practice

Do not try to solve every problem in one game. Give each game one task: danger squares beside empty corners, mobility, or the frontier discs you create. Add one endgame task when about ten squares remain: divide the empties into connected regions. A precise task gives you evidence to find in the replay.

• Use a hint for comparison, not as a replacement for thought. Choose a candidate square first, then see whether the hint lands in the same area. A different answer invites you to compare what each move protects: a corner or the next turn.
• Use undo for small experiments. If a move gives access to a danger square beside an empty corner, undo it, choose a quieter square, and observe the AI’s reply.
• Write one sentence after replay. “I chased flips here and gave away the corner” will help in the next game. “I played badly” will not.

A shared-device game is ideal for talking through moves; pause before taking a corner or passing and count the legal squares together. An online room syncs each accepted move to the opponent, so check once more before placing the disc. Online games have no undo, so do not carry repeated trial moves from practice into a game with a friend.

Frequently asked questions