About this template
Slide Fifteen is an original, self-contained browser starter. It focuses on legal neighbor moves, permutation state, and solvable shuffling. The interface and game logic live in one HTML file, so you can open the source and trace the interaction from input to screen without setting up a toolchain.
How to play
Select a tile next to the gap to slide it. Arrow keys move the empty square. Arrange 1–15 left to right, with the gap last. Use the Start button to begin and Restart to try again. The game does not connect to a server or store a public score.
What is in the download?
The ZIP includes index.html, a quick-start README, and the MIT license. There are no external scripts, fonts, image assets, or package dependencies. Open index.html in a current browser to play; open it in a text editor to make changes.
Make your first change
Adjust SHUFFLE_STEPS to change the scramble. Shuffle through legal moves instead of a random permutation, which can produce an unsolvable board.
- Save a copy of the original before editing.
- Change one value or rule, reload, and play a full round.
- Try both winning and losing paths. Then check the controls on a smaller screen.
Ideas for your own version
Start with the visual theme: adjust the background, accent color, and title. Next, add a rule that changes a decision the player makes. Prefer one well-tested mechanic over several unfinished systems. Keep a short note beside each new setting so the next person can understand why it exists.
Follow the gap
Only a tile directly above, below, left, or right of the gap can move. Finish with 1–4 in the first row, 5–8 in the second, 9–12 in the third, then 13–15 and the empty square. Arrow keys move the gap itself; selecting a tile moves that tile into the gap.
Solve in sections
Build the top row first, then work on the left side of the remaining area. Avoid disrupting a finished row while moving lower tiles into place. The opening is created by a sequence of legal slides, so it is solvable. The shuffle length is not a claim about the shortest solution. Invalid selections do not increase the move counter.
Before you publish
This is a learning starter, not a full game engine. It has no network multiplayer, cloud saving, or commercial art pack. Add your own polish, test your target browsers, and follow the publishing checklist. The included code can be adapted for personal or commercial projects under the MIT license.