Slide & Conquer

🎮 

Slide & Conquer

A beautifully crafted sliding tile puzzle — one file, zero install, infinite replays. Open it in any browser and play immediately.

1 — What it is

Slide & Conquer is a modern take on the legendary 15-puzzle, one of the oldest and most satisfying brain teasers ever devised.

The board is a grid of numbered tiles with one empty space. Your goal is simple to state and endlessly engaging to pursue:

Slide the tiles one at a time until they sit in perfect numerical order — left to right, top to bottom — with the empty space in the bottom-right corner.

The game ships in three grid sizes — 3×3, 4×4, and 5×5 — so you can pick a quick warmup or a serious challenge.

Every board is mathematically guaranteed solvable before you ever see it. No dead-ends. No frustration. Just pure puzzle satisfaction.

2 — Controls

The game supports three input methods simultaneously:

🖱 Drag to slide Grab any adjacent tile and drag it toward the empty space. It follows your cursor in real time. Release past 40% and it snaps into place.

👆 Click or tap Tap any movable tile to move instantly.

⌨ Arrow keys Slide tiles using the keyboard — ideal for speed-runners and accessibility.

On mobile, scrolling is suppressed during drag so the page stays locked while you play. The board scales beautifully from phone to desktop.

3 — Features

• Three difficulty levels 3×3 (8 tiles), 4×4 (15 tiles), 5×5 (24 tiles)
• Move counter & timer Start on first move, stop on completion
• Personal best tracker Saved locally in your browser
• Hint system A subtle nudge — no spoilers
• Dark & light themes Retro arcade dark mode + warm light mode
• Background music Tico-Tico no Fubá on loop (toggle anytime)
• Confetti celebration 🎉 Because solving it deserves flair

4 — The rules

Simple. Precise. Unforgiving.

• Only tiles adjacent to the empty space can move
• No jumping. No diagonals
• Win by arranging tiles in ascending order
• Fewer moves = better score

New Game and Shuffle always generate a solvable board. Hints cost nothing.

5 — Why some puzzles are impossible — the math

Slide & Conquer ensures you always start in the solvable universe.

Here’s the twist:

Exactly half of all possible tile arrangements are unsolvable.

An inversion occurs when a higher-numbered tile appears before a lower-numbered one.

Each move changes inversion parity (odd/even). On even grids (like 4×4), the blank row position also affects parity.

Solvability rule (4×4)

A puzzle is solvable iff:

(number of inversions + blank row from bottom) is odd

Examples

✔️ Solvable 0 inversions + row 1 = 1 (odd)

❌ Impossible Swap 14 & 15 → 1 inversion + row 1 = 2 (even)

🧠 Intuition

Think of it like two parallel universes:

• Every board belongs to one
• Every move keeps you in that universe
• You can never cross between them

Slide & Conquer ensures you always start in the solvable universe.

6 — Technical

File size     ~12 KB  Dependencies  None  Platform      Any modern browser  Input         Mouse · Touch · Stylus · Keyboard  Storage       localStorage (scores only)  Offline       Yes 

Tags

Puzzle · Casual · Browser · Mobile-friendly · No install · Dark and light mode · Keyboard accessible