How to Think in Reversi: 7 Principles for Beginners
In Reversi, whoever has more discs at the end wins. The twist is that grabbing lots of discs early often makes you lose. This page sums up what strong players actually think about in seven principles. The reasons shown by the hint feature in our Reversi game are based on exactly these ideas.
1. Care about how many moves you have, not how many discs
In the opening and middle game, what matters is not how many discs you own but how many squares you can play next. With many options you can pick a good move; with few, you may be forced onto squares you would rather avoid, such as those next to a corner.
Flipping lots of discs looks greedy and good, but it spreads your discs across the board and gives your opponent more discs to sandwich. Reduce your opponent’s moves and keep your own — that is the core idea of the middle game. The hint shows this directly as the number of moves your opponent will have after you play.
2. Squares have value: corners, X, C and edges
Not all squares are equal. Start by learning these four kinds.
| Square | Where | How to think about it |
|---|---|---|
| Corner | The four corners | Once taken it can never be flipped. Always consider it when it is available |
| X-square | Diagonally next to a corner | Playing here makes it easy for your opponent to take the corner. Avoid it while the corner is empty |
| C-square | Directly next to a corner, on the edge | Less dangerous than X, but often lets the corner go. Be careful while the corner is empty |
| Edge | The outer rim (except corners and C) | Hard to flip back, so these discs tend to stay yours |
When the hint says a square is diagonal to or right next to an empty corner, it means an X- or C-square. The ⚠ mark on the board shows a corner you are at risk of losing.
3. Don’t chase corners — deny them
A corner only becomes playable once a disc sits next to it. Whether you get a corner depends on your opponent, so what you can control is not playing next to an empty corner yourself and creating positions where your opponent has no choice but to do so.
Before you play, check whether the move lets your opponent reach a corner. When the hint warns that your opponent takes a corner, it means the corner goes to them either right away or within the expected line.
4. Flip few discs and keep your discs inside
In the middle game, moves that flip only a few discs are often the best. Discs surrounded by empty squares are material your opponent can sandwich, so they create new moves for your opponent.
Building a wall of your discs along the empty frontier opens up your opponent’s options at once. When in doubt, choose a quiet move on the inside that does not spread your discs outward.
5. Leave your opponent only bad squares
As you keep reducing your opponent’s moves, eventually only bad squares — like those next to corners — remain for them. Then your opponent hands you the corner. If they run out of moves entirely, they must pass and you play again, which is even better.
When the hint says that even your opponent’s best reply ② lands next to an empty corner, it is describing exactly this situation.
6. Read a few moves ahead: the ②③④ line
You cannot judge a move just by the position right after it. Picture a few moves ahead: you play, your opponent answers with their best move, and you play again.
The hint draws this expected line on the board as ② (opponent), ③ (you) and ④ (opponent). It compares things like corners and how many moves each side has at ④ to rank the candidates — for example “you take a corner at ③”. Tap a few candidate squares and compare their reasons.
7. In the endgame, count and read to the end
Once about 10 empty squares remain, switch your thinking. From here on, the final disc difference is all that matters. Count move by move, including your opponent’s replies.
When the empty squares are split into separate regions, the side that gets the last move in a region with an even number of empties often has the edge (the parity idea). In the endgame the hint also reads to the very end and tells you the final margin.
How to read the hint marks
- Numbers: glowing frames are recommended moves; white circles are the next options (weaker)
- Gold dashed rings: discs that flip with that move
- Red dots: squares your opponent can play next
- Small discs ②③④: the expected line; ② and ④ are your opponent, ③ is you
- ⚠: a corner your opponent takes or is aiming at