How to solve this 8×8 logic puzzle
A
B
C
D
E
F
G
H
1
2
3
4
5
6
7
8
1
2
3🐱
🐱
4
5
6
🐱
🐱
7
🐱
🐱
🐱
8
🐱
This 8×8 board rates as gentle (difficulty score 748). Solving it from scratch takes 20 logical steps, using 5 techniques: Single cell, Row/column exclusion, Adjacency clear, Region confinement, Shape squeeze. Every step below is forced: nothing here is a guess.
- First, place a marker at H1. Region has exactly one open cell left. Placing here clears the rest of row 1, column H, and its region. Placing here also clears its 1 touching neighbour.
- Next, place a marker at C2. Region has exactly one open cell left. Placing here clears the rest of row 2, column C, and its region. Placing here also clears its 2 touching neighbours.
- Then, place a marker at G3. Region has exactly one open cell left. Placing here clears the rest of row 3, column G, and its region. Placing here also clears its 1 touching neighbour.
- After that, place a marker at F5. Region has exactly one open cell left. Placing here clears the rest of row 5, column F, and its region. Placing here also clears its 2 touching neighbours.
- Now, place a marker at B4. Region has exactly one open cell left. Placing here clears the rest of row 4, column B, and its region.
- From there, every open cell left in this region sits in row 8, so its marker has to land there; that clears every other open cell in the row.
- Following that, every remaining candidate in this region touches D7 and E7, so whichever candidate ends up marked will clear them, and they can be ruled out now regardless of which one wins.
- First, place a marker at D6. Region has exactly one open cell left. Placing here clears the rest of row 6, column D, and its region.
- Next, place a marker at A7. Region has exactly one open cell left.
- Finally, place a marker at E8. Region has exactly one open cell left.
The key move here was Shape squeeze. Once you can spot that, this board falls quickly. ∎