How to Solve Sliding Block Puzzles
How the Sliding Blocks puzzle works and how to get the big block out in fewer moves: moving the gap, corner moves, bottlenecks and a worked opening.
Sliding Blocks is one of the oldest moving puzzles in the world, the kind that was once carved from wood and sold in toy shops. A tray is packed with blocks of four shapes: small squares, wide blocks two squares across, tall blocks two squares high and one big block, two by two. Two squares are empty. Blocks slide into empty squares, never over each other and never out of the tray, except the big one: there is a gap two squares wide in the bottom edge, and when the big block reaches it, it slides out and the puzzle is solved.
The rules in short
- A block slides in a straight line into empty squares, as far as you like.
- Sliding one block is one move. Sliding the same block again straight after, round a corner or back the other way, is still that one move. Sliding it back to where it started costs nothing.
- The puzzle is solved when the big block sits in the bottom two rows right above the gap.
The game shows the fewest possible moves next to your count. That number is exact: every board was solved by a computer that looked at every position its blocks can ever reach, so matching it is a perfect solve.
Think about the empty squares, not the blocks
The most useful change of view in this puzzle is to stop looking at the blocks and start looking at the two empty squares. Every move is really the gap travelling around the tray. When you want a block to go somewhere, the question is how to bring the empty squares next to it, on the side it needs to move to.
- Two empty squares side by side let a wide block slide down or up, or a tall block slide sideways.
- Two empty squares one above the other let a tall block slide down or up, or a wide block slide across.
- Two separate empty squares only ever let small blocks move, and small blocks moving one at a time is the slowest way to get anywhere.
So a large part of solving is joining the two holes into one gap of the right shape, then walking that gap around the big block.
Corner moves are free moves
Because sliding the same block again straight after still counts as one move, a small block can travel round a corner, or along an L shape, for the price of one. Use this. When a small block needs to get from one side of the tray to the other, slide it as far as it can go, then turn it and keep going before you touch anything else. Touching a second block in between turns one move into three.
The same goes for undoing a slide you regret: slide the block straight back and it costs nothing at all.
Bottlenecks and how to read a board
Most boards have one bottleneck: a place where the big block must pass and where only one arrangement of the other blocks lets it through. Common ones are:
- The big block's first step down. Two blocks usually sit right below it. Both have to leave, and they need somewhere to go.
- The middle rows. Wide blocks lying across the middle are the usual wall. A wide block can only get out of the way by moving up or down, so it needs a two-square gap above or below it.
- The last row. The big block can only enter the bottom rows above the gap if the squares on both sides of the gap hold small blocks or tall blocks pushed aside.
Before you start moving, find the bottleneck and decide where each blocking piece should end up. A plan of three or four steps saves many wasted moves.
A typical opening
Imagine the big block in the top middle of a four-wide tray, two tall blocks on its left and right, a wide block under it and two small blocks under that, with the two empty squares at the bottom. The big block cannot move until the wide block leaves. The wide block cannot move until there is a two-square gap below it. So the first moves bring the empty squares together under the wide block: slide the two small blocks down into the bottom row, one to each side. Now the wide block drops into the gap, the squares under the big block are free, and it can take its first step down. Four moves, and the board has changed completely.
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Habits that save moves
- Park small blocks in corners. A small block in a corner is out of the way of everything. A small block in the middle of the tray is in the way of the big block sooner or later.
- Keep wide blocks low and tall blocks at the sides. The big block travels down the middle of the tray; tall blocks against the walls and wide blocks below its path cause the least trouble.
- Move the big block whenever it can go down. Each step down is progress that is rarely undone. If it must go back up later, that is usually a sign the plan needs another look.
- Count before you commit. On medium and hard days, try to say the next three moves out loud before making them.
Difficulty, scoring and the leaderboard
| Level | Tray | Fewest moves |
|---|---|---|
| Easy | 4 × 5 squares | about 8 to 18 |
| Medium | 4 × 5 squares | about 24 to 45 |
| Hard | 4 × 6 squares | 50 or more |
The ranking is by moves first, then by time, and only a member's first solve of the day counts. Undo and Start over are free: undone moves are not counted, so you can explore an idea and take it back. The hint for the big block is always the same: work out where the gap must be for its next step, then walk the gap there.
When you are stuck
- Find the block directly in the way of the big block's next step.
- Ask where that block could go, and what is in the way of that.
- Bring the empty squares to that spot, joined into the right shape.
- Repeat until the big block can move, then start again from step one.
Followed patiently, this chain of questions solves every board, and with practice it starts to find the short solutions too.
Play it now
- Sliding BlocksSlide the wooden blocks aside to get the big one out.
- Car EscapeSlide the cars and trucks aside to let the red car out.
Every game is free in your browser, with nothing to download; the daily puzzles change at midnight and the archive keeps the last 60 days. See all the logic games.
Questions and answers
What counts as a move?
Sliding one block anywhere it can go in one go. Sliding the same block again straight after, round a corner or back, is still the same move, and sliding it back to where the move started costs nothing.
Is the fewest possible moves really the minimum?
Yes. Every board was solved by a complete search of every position its blocks can reach, so the number shown is exact.
Can a block jump over another?
No. Blocks only slide into empty squares, in straight lines, and only the big block can leave the tray, through the gap.
How is it ranked?
Fewest moves first, then the fastest time. Only a member’s first solve of the day is ranked.
Written by the DailyGameClub team from the rules as DailyGameClub plays them. Updated October 16, 2026. New to a word? See the glossary. Spotted a mistake? Tell us.