Let fire or flood creep across a tile board and flow around the walls

When a puzzle board catches fire or fills with water, the effect should spread from the source like it really travels. If it grows as a circle it jumps through walls and lights tiles it could never reach, while tiles in sealed pockets must stay untouched. Here is how to time every tile.

Why this works

Fire and water travel through the space they can actually reach, so what matters is the number of steps around the walls, not the straight distance. A tile behind a wall must wait for the long way round.

When not to use it

Don't use it when the effect should leap, such as fire jumping across a gap or water seeping through a wall. Add those special links by hand, or the spread will never cross.

In the full entry

• What to build, step by step
• Starting values and the reason for each
• 3 common mistakes and the fix
• 31 lines of example code with 4 checks that pass
• How your AI shows you that it works

Say this to your AI

Use the Spielerando entry "Let fire or flood creep across a tile board and flow around the walls" (read_entry fire-or-water-spreads-tile-by-tile-around-walls) in my game. Build it step by step, and show me how you checked that it works.

Or skip this and connect the MCP: your AI then finds all of this by itself.Connect the MCP