Fire spread

Owns a burning state per cell, tile, or object (unburnt, burning, burnt), often with fuel and heat values. Each tick a burning unit consumes fuel and tries to ignite neighbors with a chance or rate scaled by their flammability, moisture, and wind direction; it goes out when fuel runs out or when water, rain, or firefighters remove it. Inputs are material flammability, weather, and suppression; outputs are destroyed structures and terrain, heat, and sometimes smoke or updrafts. SimCity spreads fire between flammable tiles and fire stations put it out; Breath of the Wild's chemistry engine lets fire change the state of materials such as grass, whose burning creates updrafts, and rain stops it; Far Cry 2 and Dwarf Fortress propagate fire through grass and trees.

A small spark becomes an emergency. The player races to contain fire before it reaches stockpiles or homes, or uses it as a tool: burning a field to clear it, lighting grass to drive enemies, or riding the updraft. Fire teaches the player to read the map as fuel and firebreaks.

• ignition sources and their rates: lightning, overheating, arson, player tools
• flammability, fuel load, and burn duration per material
• spread probability per neighbor and the wind bias on it
• moisture and weather modifiers, such as rain suppressing ignition
• suppression tools: water, firefighters, fire station coverage, firebreak materials

• Spread tuned slightly too high burns the whole map before the player can react; slightly too low makes fire a nonevent.
• Fire that ignores construction choices, such as stone burning like wood, removes the decision space.
• Large burning areas in cell-based implementations cost noticeable frame time during big fires.

• Players build firebreaks and separate flammable storage, which changes settlement layout.
• Fire couples with weather and terrain: dry seasons and wind produce larger fires, and rain ends them.
• Players repurpose fire as a weapon or tool, such as burning grass under enemies or clearing forest.

• Can learned combustion and smoke surrogates make fire visually rich while its spread stays readable and controllable?