Sokoban deadlocks: check where you can stand before pushing

The most important square in Sokoban is often the one behind a box. A clear route from the box to a green target does not help if your player cannot get into position to push along that route.

In TAPA GAME's twenty warehouses, you can push one box at a time, but you cannot pull it. Undo lets you take back a move, and Retry resets the current level. Use those controls to investigate a route before committing to a long chain of pushes.

Recognize a corner that cannot be repaired

A box pushed into a corner formed by two walls cannot leave through ordinary movement. If that square is not a target, the position is a deadlock. Check the destination square before the push, not after it.

A target in a corner is different: a box can belong there. Even then, make sure placing it does not block a passage that another box still needs. Finishing one target early can make the rest of the warehouse impossible.

Walls can trap boxes without a corner

A box against a wall can move along that wall only if you can stand behind it for the required push. If every target is away from the wall, the box may already be stuck because you cannot get between it and the wall to push it outward.

Two boxes can also block each other. If neither has a reachable pushing square, an open area in front of them does not solve the problem. Trace the player's walking route as well as the boxes' routes.

Work backward from a target

Pick one green target and decide which direction the final box push would come from. Then locate the square where the player must stand for that push. Repeat that check one step backward along the planned route.

This reveals places where a box can turn and places where it cannot. A narrow corridor may carry a box straight through, but offer no position from which to push it sideways. Keep that limitation in mind when choosing which box will serve which target.

Use Undo to test a specific question

A useful test is: after this push, can I walk around the box and reach the next pushing square? Make the move, inspect the available path, then undo if it closes the wrong corridor. Repeating a random move teaches less than checking one clear condition.

Move with swipes, the directional buttons or keyboard arrows. U undoes and R retries the level. Before putting a box on its target, make one final check of the other boxes' access routes. A solved-looking section can still be the doorway needed by the rest of the board.