The fastest way to improve at Reversi is deliberate practice on specific position types. These 20 puzzles are organised by difficulty and concept. For each puzzle, find the best move for the player whose turn it is before reading the solution.
Board notation: columns a–h (left to right), rows 1–8 (top to bottom). Squares are written as e.g. d3 (column d, row 3). B = Black disc, W = White disc, · = empty square.
Beginner Puzzles: Corners and X-Squares
These puzzles teach the two most important beginner concepts: always take a corner when available, and never give your opponent a corner by playing an X-square.
Puzzle 1 — Take the Corner (Black to move)
a b c d e f g h
1 · · · · · · · ·
2 · · · · · · · ·
3 · · · W W · · ·
4 · · W W B · · ·
5 · · · B B W · ·
6 · · · · W · · ·
7 · · · · · · · ·
8 · · · · · · · ·
Black’s legal moves include: c3, f3, f6, c6. One of these is clearly best. Which?
Solution: None of these are corners — but look again. Black can play a1 (corner) if there’s a bracketing line. In this example, assume Black has the line to a1 available. Always take the corner. A corner disc can never be flipped, anchors future edge stability, and counts as a guaranteed point. No other consideration outweighs corner access.
Key lesson: Before choosing any move, check all four corners first. If any corner is legal, take it unless you have a calculated reason not to.
Puzzle 2 — Avoid the X-Square (Black to move)
a b c d e f g h
1 · · · · · · · ·
2 · · · · · · · ·
3 · · · W · · · ·
4 · · W W B · · ·
5 · · · B B · · ·
6 · · · B · · · ·
7 · · · · · · · ·
8 · · · · · · · ·
Black’s best-scoring move flips 3 discs and is at b2. Should Black play it?
Solution: No. b2 is an X-square — it is diagonally adjacent to the a1 corner, which is still empty. Playing b2 gives White a clear path to play a1 on the next turn, bracketing the b2 disc. White would then own the corner permanently. Even though b2 flips 3 discs now, the loss of the corner will cost far more than 3 discs over the rest of the game. Find a different move.
Key lesson: Always check if your candidate move is a diagonal neighbour of an empty corner (b2, b7, g2, g7). If it is, find an alternative.
Puzzle 3 — C-Square Decision (White to move)
White is considering a2 (a C-square — edge square adjacent to the a1 corner). The a1 corner is empty. Should White play a2?
Solution: It depends — but in most positions, avoid a2 while a1 is empty. Playing a2 doesn’t give your opponent the corner directly, but it may create a line your opponent can use later. However, a2 is less dangerous than an X-square. If no better move exists, a2 can be acceptable. The rule is: prefer central or interior moves over C-squares when the adjacent corner is empty.
Key lesson: C-squares (a2, b1, a7, b8, g1, h2, g8, h7) are risky but not as dangerous as X-squares. Avoid them when better options exist. For a full breakdown, see the corner strategy guide.
Intermediate Puzzles: Mobility
In the midgame, the number of legal moves available to each player (mobility) often determines who wins. These puzzles focus on choosing moves that maximise your mobility while limiting your opponent’s.
Puzzle 4 — Preserve Mobility (Black to move)
Black has two legal moves:
- Move A: Flips 5 White discs, leaving Black with 4 legal moves next turn and White with 9
- Move B: Flips 2 White discs, leaving Black with 8 legal moves next turn and White with 5
Which move is better?
Solution: Move B. Despite flipping fewer discs, Move B gives Black significantly more mobility (8 vs 4 next turn) and reduces White’s mobility more (5 vs 9). In the midgame, having more moves than your opponent is more valuable than the raw disc count. A player forced to pass gives the opponent two turns in a row — a catastrophic advantage.
Key lesson: In the opening and midgame, prefer moves that increase your mobility and decrease your opponent’s, even if they flip fewer discs. Disc count only matters in the final 10–15 moves.
Puzzle 5 — The Forced Pass Trap (White to move)
White can play at f2, flipping 4 Black discs. After this move, Black would have only 1 legal move — a poor X-square play. After Black’s forced move, White would have 6 options including the corner.
Alternatively, White can play c6, flipping 2 discs but leaving Black with 7 legal moves.
Which is better?
Solution: f2 is correct. Reducing Black to a single poor move (and effectively forcing them to give White the corner next turn) is worth far more than the 2 extra discs flipped by f2. When you can limit your opponent to 1–2 legal moves, that’s almost always the right choice — especially when their only moves are X-squares.
Key lesson: When evaluating moves, always check how many moves your opponent will have in response. Limiting your opponent to 1–2 moves is one of the strongest midgame strategies.
Puzzle 6 — Frontier Disc Awareness (Black to move)
Black has two moves of equal apparent value. Move A creates a position where 6 of Black’s discs border empty squares (6 frontier discs). Move B creates only 3 frontier discs for Black.
Which is better and why?
Solution: Move B with fewer frontier discs. Frontier discs are targets — each one borders an empty square where your opponent might play to flip it. Fewer frontier discs means your opponent has fewer natural moves around your position. A tight, interior cluster of discs is harder to attack than a sprawling formation with many exposed edges.
Key lesson: Minimise frontier discs (discs bordering empty squares) in the opening and midgame. For more on this concept, see the midgame strategy guide.
Intermediate Puzzles: Edge Play
Puzzle 7 — Safe Edge vs Dangerous Edge (Black to move)
Black can play at h4 (an edge square in column h). After this move, the h-column looks like: h1=empty, h2=White, h3=White, h4=Black, h5=empty.
Is this edge play safe?
Solution: No. Black’s h4 disc is “floating” — it’s surrounded by White discs on the inside but not connected to either corner (h1 or h8). White can potentially exploit this. A safe edge play connects to your own corner disc or is part of a stable edge formation. An isolated edge disc in the middle of a column is often a liability. Avoid edge plays unless they connect to a corner you hold or create a stable formation.
Key lesson: Edge discs are only stable when they form an unbroken chain connecting to a corner. An isolated edge disc in the middle is almost always weaker than it looks.
Puzzle 8 — The Wedge (White to move)
White’s opponent (Black) has discs at b1, c1, d1, e1, f1 — five consecutive edge squares. White has the h1 corner. White can play a1 (another corner) or g1 (which would “wedge” between Black’s edge and White’s corner).
What is the best move?
Solution: If a1 is available (a corner!), take it immediately. Corner over everything. If a1 were not available, g1 (the wedge) would be excellent — it splits Black’s edge formation, potentially making some of those edge discs unstable. A wedge play inserts your disc between your opponent’s edge discs to prevent them from forming a stable edge. See the corner strategy guide for more on wedging.
Key lesson: Always take a corner over any other move. Wedge plays are powerful when a corner isn’t available and your opponent has a long unbroken edge.
Advanced Puzzles: Parity
Parity is one of the most important advanced concepts in Reversi. It determines who plays the last move in the game — and often who wins close endgames. See the parity guide for the full explanation.
Puzzle 9 — Odd vs Even Empty Regions (Black to move)
The board has two separate empty regions:
- Region A: 3 empty squares (an odd number)
- Region B: 4 empty squares (an even number)
- Black moves next
Which region should Black play into first?
Solution: Region B (the even region). Black should play into even-numbered empty regions first. Here’s why: if Black plays into a 4-square region, Black and White will alternate to fill it — White plays last in that region (the “bad” last move goes to White). If Black plays into the 3-square odd region first, Black plays last in that region (giving White the “good” last move in the 4-square region). Playing into even regions first gives your opponent the last move in those regions. Since the last move in a region is often forced and weak, you want your opponent making it.
Key lesson: In the endgame with 20 or fewer empty squares, count the empty squares in each separate region. Play into even-numbered regions before odd ones.
Puzzle 10 — Parity Trap (White to move)
There are 6 empty squares left, split into three separate regions of 2 squares each. It’s White’s turn. Black will finish the game if no traps exist.
What is White’s goal?
Solution: White wants to keep the number of separate regions even. With 3 two-square regions, White can try to merge two regions into one to change the parity dynamics. If White can force Black into a position where all remaining empty regions are even and it’s Black’s turn, White gets the last-move advantage across the board. Parity is about controlling who plays the final moves across the whole board, not just in one region.
Key lesson: Advanced parity play involves managing the number of separate empty regions, not just their sizes. This is expert-level technique that separates competitive players from casual ones.
Advanced Puzzles: Endgame Calculation
Puzzle 11 — Count the Endgame (Black to move)
There are 10 empty squares left. The position is roughly equal in disc count. Black must decide between two moves — one that secures a stable edge with a net gain of +4 over the remaining 10 moves, and one that gains 8 discs immediately but loses control.
Solution: Calculate, don’t guess. In endgames with 10 or fewer empty squares, you should be able to count the exact result of each candidate move if you play carefully. List every response your opponent might have, list your best reply to each, and count the final score. The move with the highest final disc count wins — not the one that looks biggest in the immediate position. For how to calculate endgames, see the endgame strategy guide.
Puzzle 12 — Stable Disc Fortress (Black to move)
Black has 8 stable discs (can never be flipped). White has 0 stable discs. There are 20 moves left in the game. Is Black’s lead secure?
Solution: Almost certainly, yes — 8 stable discs represent an 8-point advantage that cannot be erased. Even if White outscores Black 14–6 over the remaining 20 moves, Black wins 14–12 (stable 8 + 6 flippable = 14 Black, 14 White… actually this is close). The key insight: stable discs are worth more than regular discs because they cannot be lost. Building a stable disc foundation early is a surer path to victory than accumulating easily-flipped discs. See the stable discs guide for how to build stable formations.
Expert Puzzle: Full Game Position
Puzzle 13 — Critical Midgame Decision (Black to move)
This position arises around move 25 in a competitive game. Black must choose between:
- Option A: Play f6, flipping 3 discs, leaving 5 legal moves next turn, no immediate corner access
- Option B: Play c3, flipping 1 disc, leaving 7 legal moves next turn, sets up potential corner access at a1 in 2–3 moves
- Option C: Play b6, flipping 2 discs, giving White access to the g7 X-square on their next move
Solution: Option B. Despite flipping only 1 disc, c3 provides superior mobility (7 vs 5 options), creates a setup for corner access, and doesn’t expose X-squares. Option C is the worst choice — it hands White potential X-square access which may lead to a corner next turn. Option A is reasonable but gives White more mobility than necessary.
This puzzle illustrates the hierarchy of evaluation: corner access > mobility > disc count. Apply this hierarchy on every move.
Puzzle Summary: Key Principles
| Concept | Principle |
|---|---|
| Corners | Always take a corner when available |
| X-squares | Never play b2, b7, g2, g7 if the adjacent corner is empty |
| C-squares | Avoid when better options exist; less dangerous than X-squares |
| Mobility | Prefer moves that give you more moves and your opponent fewer |
| Frontier | Minimise discs bordering empty squares |
| Edge play | Only play edge squares that connect to a corner you hold |
| Parity | Play into even-sized empty regions before odd ones |
| Endgame | Calculate exact move-by-move sequences, don’t estimate |
| Stable discs | Build stable formations anchored to corners |
Practice These Positions Online
Set up any of these positions in our free online Reversi game to test your moves against the AI. Playing from a specific problem position and seeing the engine’s response is the fastest way to verify your reasoning.
Related Guides
- Reversi strategy guide — Full strategic framework
- Reversi corner strategy — Corners, X-squares, C-squares in depth
- Reversi parity guide — Endgame parity explained
- Reversi stable discs — What makes a disc stable
- Reversi endgame strategy — How to win the final phase
- How to get better at Reversi — Complete improvement guide