Sokoban Puzzle Guide: Backward Solving and Deadlock Avoidance

Sokoban is logic at its purest: no luck, no time pressure — just you against the level designer's mind. Boxes can be pushed but never pulled, and one wrong move can sink the whole board, so the solution matters a hundred times more than your speed.

How to Play

Steer the warehouse worker with the arrow keys, pushing boxes onto every marked goal square to clear the level. You can push only one box at a time, and only push — never pull. Once a box slides into a corner or gets jammed where it can no longer move, the level is deadlocked and usually must be restarted.

Pro Tips

1. Backward solving is the master key: don't brute-force from the start. Stare at a goal square and ask "for the final push, which direction does the box come from?" Then work out the second-to-last push... all the way back to the opening position, and the route writes itself.
2. Play the forced moves first: some boxes are pinned by walls and neighbors with exactly one push available. Sort out these no-choice moves at the start — they're the skeleton of the whole solution.
3. Memorize the deadlock checklist: a box in a corner is dead; two boxes side by side against a wall are dead. Before every push, ask "where can this box still go afterward?" — a three-second check saves ten minutes of restarting.
4. Keep maneuvering room: leave enough space between boxes for them to slide past each other. Never cram three into a clump — a clump almost guarantees one ends up in a corner.
5. Think about the worker before the box: it's the worker who pushes. Before every push, confirm they can walk around to the required side — a worker sealed in by boxes has lost both hands and both feet.
6. Restart on deadlock, instantly: deadlock is irreversible; shuffling around in a lost position only wastes time. Restart without ceremony and take the lesson into a new route.

Common Mistakes

• Improvising one push at a time: no overall plan, pushing wherever convenient — until midgame, when the key box turns out to be walled in by your own doing.
• Watching boxes, forgetting the worker: the boxes line up beautifully, but the worker is standing on the side they can never get around.
• Refusing to restart: knowing it's deadlocked yet trying again and again, letting the frustration snowball.

Advanced Strategy

Picture each level as a state graph: every position is a node, every push is an edge, and you're searching for the path from start to "all boxes home." Backward solving works because nodes near the finish are few and clear — traveling upstream beats bumping around downstream. Give yourself a rule during practice: if two consecutive pushes lack a clear purpose, stop and re-think. It forces you to push with a plan at all times instead of being dragged by the position. After a dozen levels or so, you'll start "seeing" the board several moves ahead.

Related Guides

• Slide Puzzle Guide — the same spatial-logic training.
• Sudoku Guide — pure logical deduction in another form.
• Minesweeper Advanced Guide — rule-based, fully deterministic reasoning.