Rain

Rain is liquid precipitation. In Wars World, it is the condensation of atmospheric water vapor into drops heavy enough to fall, often making it to the surface. Rain is the primary source of fresh water for most areas of the world, providing suitable conditions for diverse ecosystems, as well as water for hydroelectric power plants and crop irrigation. However, not all rain reaches the surface; some evaporates while falling through dry air.

Advance Wars

Rain falling on an Advance Wars 2 battlefield

Rain causes the movement cost to increase for tread and tire movement classes in woods and on plains. Units under the command of Drake are unaffected by rain; his CO Power also causes it to rain. Additionally, units commanded by Olaf are affected more by the rain than other COs; his units get the same penalty in rain as the other COs get in snow.

Advance Wars 2: Black Hole Rising

In Advance Wars 2, rain has the same effect as in Advance Wars 1, increasing movement cost for vehicles on natural terrain; in addition, Olaf gains movement penalties similar to snow and Drake's and Sturm's units are unnaffected by it. On top of that, Drake's powers make it rain for one turn.

Advance Wars: Dual Strike

Rachel screams while her fireworks fizzle out

Advance Wars: Days of Ruin

When raining, Fog of War appears even if there wasn't any present before the weather change and visibility is lowered by 1. Mobility remains unchanged.