Rite of Way
Elemental Damage and basic physics
This isn’t pokemon but common-sensical laws of physics for elemental spell damage interaction should apply. For cases of extra damage, expect your spell stat modifier to be multiplied. Damage reduction will depend on the situation.
Here are some common sense situations:
Lightening does extra damage in ice or water.
Lightening does reduced damage if your character is incased in stone (different from petrified) or grounded in some clever way.
Fire damage is multiplied against flammable objects and gasses, or poison clouds.
Fire damage is halved in a heavy downpour. Fire spells are un-castable under water and things below the surface of a pool of water are pretty much immune unless the spell is massive. (this will be at my discretion)
Ice and water spells do reduced damage in fires and lava.
People frozen in ice have a shatter value. If they take over 50% of their total (not remaining) hitpoints in one hit, they explode.