Staring at an Akari puzzle and not sure where to start? These five strategies will take you from confused to confident. Each technique builds on the last — master them in order and you will be solving Medium puzzles in no time.
Strategy 1: Start with Extremes
Scan the grid for "0" and "4" cells first. These give the most information with zero effort:
- "0" cell: None of its four neighbors can hold a bulb. Mark all four with X immediately.
- "4" cell: All four neighbors must be bulbs. Place cats in all four positions right away.
After handling extremes, check "3" cells with one neighbor already blocked, and "1" cells with three neighbors blocked. These are nearly as informative.
Strategy 2: Propagate Before You Think
After every placement, immediately check what it triggers. A newly placed bulb illuminates its entire row and column — which means:
- No other bulb can go in the same unobstructed line (conflict rule)
- Numbered cells adjacent to the new bulb may now be satisfied
- Dark cells near the new bulb may now have fewer possible light sources
Do not place a bulb and move on. Propagate its consequences before touching another cell.
Strategy 3: Hunt Dark Cells
Dark cells (unilluminated white cells) are your compass. For each dark cell, count how many valid positions could illuminate it:
- One source: A bulb must go there. Place it.
- Two sources: You need more information before deciding.
- Zero sources: You made an error somewhere — backtrack.
This "last remaining option" technique is the most common way to break through a stuck position.
Strategy 4: Use X Marks Liberally
X marks are not cheating — they are thinking tools. Right-click (or long-press on mobile) to mark cells where no bulb can go. Benefits:
- Reduces cognitive load — you do not need to remember eliminations
- Makes forced moves obvious — when all but one neighbor is X, the remaining cell is forced
- Prevents accidental bulb placement in eliminated positions
Strategy 5: Shadow Mapping (Advanced)
For Hard puzzles, mentally overlay a "shadow map" on the grid. For each undecided cell, track which directions could still illuminate it. As you place bulbs and mark impossibilities, the shadow map narrows. When a cell shows only one viable direction, that direction is forced.
This systematic approach prevents you from overlooking subtle deductions on larger grids (12×12 and above).
Practice These Strategies
Theory is nothing without practice. Start with GridPaw's Easy 7×7 puzzles to build muscle memory, then graduate to Medium and Hard. Use the Hint button when stuck — it shows you which cell to focus on, helping you learn which strategy applies.