Box Pusher Guide: Avoid Corner Deadlocks

A Box Pusher guide starts behind the crate

The important square in a box-pushing puzzle is often the one behind the crate. To push upward, you must stand below it, and the destination above it must be empty. Reaching a crate is therefore different from being able to move it in the direction your plan needs.

This Box Pusher guide covers ProjectGAMR's fixed two-crate board as checked on October 21, 2026. It uses classic push-only rules: move horizontally or vertically, push one crate at a time and never pull. Walls and other crates block movement. Complete the puzzle by placing a crate on each of the two purple goals.

Separate a walking route from a pushing route

Before moving a box, identify its intended next square and the square where your player must stand. Then check how you will reach that standing square. A floor tile can be reachable for the player while the same tile is a poor destination for a crate, because their movement possibilities differ.

On the local board, the player begins between two vertically aligned crates, each one square from its goal. There is no need to take either crate on a sightseeing trip around the room. The open space to the sides helps you walk, but extra room does not make every push useful.

Recognize a non-goal corner before entering it

A crate in a corner without a goal cannot be recovered through ordinary forward play under these rules. The two walls stop pushes toward them. Moving away from either wall would require the player to stand inside that wall. Undo can reverse the mistake; walking around the room cannot create that missing standing space.

Use the full seven-by-seven grid for coordinates, including the surrounding walls: the upper-left square is row 1, column 1. Row 2, column 2 is the upper-left interior corner, and it is not a goal. The upper goal is at row 2, column 4. A crate in the corner remains two columns away but has lost every legal push direction.

Solve the starting position in three moves

Start from New game. Press Up once: the upper crate moves onto the upper goal. Press Down once to return the player to the central starting square. Press Down again: the lower crate moves onto the lower goal. The result is two occupied goals after three accepted moves, including two pushes.

These directions were checked against the actual local game, rather than copied from an unrelated Sokoban level. Direction buttons and arrow keys express the same movement choices. The move counter includes ordinary walking as well as pushing, so two completed crate deliveries do not imply a counter reading of two.

Use Undo to inspect why a plan failed

An optional counterexample makes the corner visible. From a fresh start, press Right, Up, Left, Left, Down, Left, Up. The final push places the upper crate in the non-goal corner at row 2, column 2. Inspect the walls before continuing: the remaining walking space does not provide a way to push that crate out.

Press Undo to reverse the last accepted move, then keep undoing if you want the complete starting arrangement back. In this implementation, Undo restores the player, crate positions and move count. New game instead restarts the fixed board immediately. Distinguish that behavior from other ProjectGAMR puzzles whose New game button generates a different position.

Keep a goal assignment open to revision

The simple local layout gives each crate an immediate goal, but larger push-only puzzles can require more careful assignments. The JSoko developer's deadlock explanations show why checking one movable crate alone is insufficient: the whole arrangement can fail even when individual boxes still have possible moves.

For this board, use a short routine before each push: name the destination, locate your standing square and check whether the crate will still have the mobility it needs. A successful walking route answers only the middle question. Planning all three keeps a harmless-looking step from becoming a corner deadlock.

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