Happy Life GamesHow to Solve a Slide Puzzle: Rules, Row-by-Row Method and Tips for Par
The sliding tile puzzle is one of the oldest puzzles still in everyday use. Its best-known form, the 15 puzzle, was a genuine craze around 1880. Our Slide Puzzle keeps the classic idea: a picture is cut into square tiles, one tile is taken out to leave a gap, and the rest are shuffled. You slide tiles into the gap, one at a time, until the picture is whole again.
Part of the appeal is watching a jumble of colors turn back into a scene. The other part is the quiet challenge of doing it efficiently, because every level also gives you a par, the fewest moves it can be solved in.
How to play
At the top of the screen you'll see a small framed preview of the finished picture, its name (such as Kitty Meadow or Whale Bay), and a counter showing your moves against par. Below it sits the board.
- Tap a tile next to the gap, directly above, below, left or right of it, and it slides into the empty space. Tapping a tile that isn't next to the gap just makes it wobble.
- Each slide is one move. Tiles move one at a time; there's no sliding of a whole row in a single tap.
- Win by putting every tile back in its home position. The gap belongs in the bottom-right corner, and when the picture is complete, the missing tile flies in from the preview to fill it.
From level 3 the tiles carry small numbers, counting left to right and top to bottom, so you always know where each one belongs even when parts of the picture look alike. A small sparkle appears whenever a tile lands in its home spot.
Finishing at or under par earns a "PERFECT!" message; finishing over par still wins the level. There is no move limit, but if you wander far past par (more than twice par plus a few moves) a gentle reminder suggests using undo or a hint. Undo takes back one slide, Hint highlights the next tile to move with an arrow toward the gap, and Skip moves on.
Beginner strategy: the row-by-row method
For any size of board, the dependable approach is to solve it in layers, locking in finished parts so you never have to disturb them again.
- Solve the top row. Bring tiles 1 and 2 into place first. The last tile of the row is the tricky one: move it to the spot just below its home, bring the gap around, and slot it in by briefly lifting the tile beside it out of the row and back.
- Solve the next row the same way, without touching the finished row above.
- Finish the last two rows together. Once only two rows remain, work column by column from left to right: place the top tile of a column, then the one beneath it, then move on.
- Rotate the final square. The last three tiles and the gap share a 2 by 2 block. Cycle them around that block until they line up.
On a 3 by 3 board this means solving the top row, then handling the last two rows column by column. On 4 by 4 and 5 by 5 boards you simply solve more rows first. You can also solve the left column after each row to keep the remaining area square, which many players find easier.
Advanced techniques for hitting par
Remember the scramble is shallow
Our levels aren't random shuffles. Each one is made by sliding tiles away from the solved picture, and par is usually somewhere between 2 and about 24 moves. That means much of the board is already close to right. A full row-by-row solve will work, but it often takes far more moves than par. To hit par, look for the short route back.
Follow the gap backward
Because the gap ends in the bottom-right corner, think about the path it must travel to get there. Tiles that are out of place usually lie along the route the gap took when the level was scrambled. Find that trail of displaced tiles and you've found most of the solution.
The obvious slide is often a trap
From level 3 the game says it outright: the move that pushes a tile straight toward home is often not the best one. The quickest solution may first move a tile away, or briefly disturb a tile that already looks right, so the gap can loop around efficiently. If the greedy move keeps leaving you over par, try the slide that looks backward.
Plan in loops
Most efficient solutions move the gap in small cycles, around a 2 by 2 or 2 by 3 block, rotating several tiles at once. Before moving, picture which loop would carry two or three tiles closer to home together.
Common mistakes
- Breaking finished rows. When solving layer by layer, avoid moving a placed tile unless you're deliberately using it to slot in the last tile of the row.
- Chasing one tile at a time. Dragging a single tile home while ignoring its neighbors often scatters them. Look at what each slide does to the tiles around it.
- Going back and forth. Sliding the same tile in and out wastes two moves. If you've lost your way, use undo rather than shuffling.
- Ignoring the preview. The small frame at the top is your map, and on the first two levels, which have no tile numbers, it's the only guide. Match colors and shapes, especially along edges.
What changes in later levels
The first ten levels use a 3 by 3 board with eight tiles, and par climbs from 2 moves to around 11. From level 11 some levels switch to a 4 by 4 board with fifteen tiles, the classic 15 puzzle size, and from level 51 the occasional 5 by 5 board appears, with 24 tiles. Every tenth level is marked as a BOSS level with a longer par and often a bigger board, and the level after it is lighter. The picture also changes each level, cycling through twelve scenes such as Teddy Party, Panda Grove, Autumn Fox and Dream Castle.
FAQ
Is every level solvable?
Yes. Each level is created by sliding tiles out of the finished picture, so it can always be slid back. (A well-known property of these puzzles is that half of all random arrangements are impossible, which is why we never shuffle tiles randomly.)
Do I have to reach par?
No. Any finished picture wins. Par is there for players who want an extra challenge.
Can I move several tiles in one tap?
No. Only one tile next to the gap moves per tap, and each counts as one move.
Does the hint follow my current board?
Yes. It calculates the shortest route from where your tiles are now, so it helps even after a detour.