About Akari
Akari (also known as Light Up) is played on a grid of white cells and black walls, some of which show a number. You place light bulbs in white cells; each bulb lights its entire row and column until blocked by a wall. The goal is to light every white cell, with no two bulbs shining directly on each other, while every numbered wall touches exactly that many bulbs.
The Rules
Place light bulbs in white cells so every white cell is lit, no two bulbs shine on each other, and each numbered wall matches its touching bulb count.
Step by Step
- The grid has white (open) cells and black wall cells; some walls show a number.
- Placing a bulb lights its entire row and column in a straight line, stopping at the first wall it hits.
- No bulb can be in the direct line of sight of another bulb.
- A numbered wall must be touched (up/down/left/right) by exactly that many bulbs.
- The puzzle is solved when every white cell is lit and every wall's bulb count matches its number.
Tips & Strategy
- A wall numbered 0 means none of its touching cells can hold a bulb — mark them immediately.
- A wall numbered 4 (or matching the number of open sides it has) forces a bulb into every one of its touching cells.
- A white cell boxed in on three sides by walls or the grid edge often has only one direction it can be lit from — trace that back to find where the bulb must go.
- Once you place a bulb, immediately mark its entire row and column (up to the next wall) as lit and bulb-free.
Frequently Asked Questions
How far does a bulb's light travel?
In a straight line up, down, left, and right from the bulb, until it hits a wall or the edge of the grid.
Can two bulbs be in the same row if a wall is between them?
Yes — the 'no shared light' rule only applies if nothing blocks the line of sight between them. A wall between two bulbs makes both placements valid.
Do unnumbered walls have any rule?
No — only numbered walls require an exact touching bulb count. Unnumbered walls simply block light and can't hold a bulb.
