Game modes

Everything we know about slide puzzles, organised by what you want to do — play a particular size, solve one, turn a photo into one, or read the maths behind why some boards are impossible.

Articles Game modes Solver & solutions Custom & photo puzzles Who it is for Math & theory
8 Puzzle — The 3×3 Slide Puzzle, Rules & Strategy

What the 8 puzzle is, how to play, the standard top-row-then-left-column strategy, and why it is a foundational benchmark for AI search.

15 Puzzle — The Classic 4×4 Slide Puzzle

What the 15 puzzle is, where it came from, how to play and solve it, and how it compares to the 8 puzzle and the larger 24/35 boards.

24 Puzzle — The 5×5 Slide Puzzle

The 24 puzzle (5×5 slide puzzle) explained: rules, history, solve time, what changes from the 15 puzzle, and why optimal solvers need pattern databases here.

35 Puzzle — The 6×6 Slide Puzzle

What the 35 puzzle (6×6 slide puzzle) is, who plays it, how long it takes, and why bigger boards become a research curiosity.

Number Slide Puzzle — Plain Tiles, No Picture

What a number slide puzzle is, how it differs from picture variants, why numbers are the default for solvers, and when to pick them over photos.

Klotski — The Classic Sliding Block Puzzle Explained

What Klotski is, how it differs from the 15 puzzle, the Huarong Dao legend, the 81-move minimum solution, and a strategy that actually works.

Sliding Block Puzzle — Every Kind, and How to Beat Them

A guide to sliding block puzzles: the tile-sorting family (8/15/24 puzzle), the block-escape family (Klotski, Rush Hour), strategy for each, and why the general problem is PSPACE-complete.

Sliding Tile Puzzle — The Whole Family Explained

A guide to the sliding tile puzzle family: square grids, hexagonal variants, rotation puzzles, and the maths that ties them together.