Lights Out — classic 5x5 lights toggle puzzle: click any cell to flip it and its 4 orthogonal neighbors. Goal: turn every light off. 30 hand-crafted unique-solution levels across 5 difficulty tiers from Beginner to Expert.
LIGHTS OUT
Classic toggle puzzle · 5×5 grid · 30 levels
How to Play
•You start with a 5×5 grid where some lights are on.
•Tap any cell to flip it and its 4 orthogonal neighbors (up, down, left, right).
•Your goal: turn every light off.
•Every puzzle has a unique solution — there's exactly one right combination of taps.
•Use Hints (3 per level) to reveal one correct tap; or restart and try again.
Why Lights Out?
Lights Out is a 1995 Tiger Electronics handheld classic. The puzzle looks simple: a 5×5 grid of lights, click any cell to flip a cross. But the cascading toggles create deep logic chains — a single tap can ripple across the entire board.
The math behind Lights Out: the toggle matrix over GF(2) has rank 23 with a 2-dimensional kernel, so every solvable state has exactly 4 equivalent solutions (one per coset). We pick the canonical “smallest” solution as the unique answer.
30 levels across 5 tiers from Beginner (1–3 presses) to Expert (17–22 presses).
Choose Level
0 / 30 solved
Level 1
Beginner · 5×5
⏱0:00
💡3
Lights Out — Rules
Lights Out is a classic puzzle. The grid has some lights on and some off.
Tap any cell to toggle that cell and its 4 neighbors (up, down, left, right). Diagonal neighbors are unaffected.
Goal: all lights off.
Buttons:
• Hint (3/level): reveals a correct tap with a glow.
• Check: validates the current state.
• Restart: reloads the level.
30 levels across 5 tiers. Each puzzle has a unique canonical solution.