I agree that the way it is currently can be pretty weird -- damage should be based on time spent, not movement.
Example 1: I cast Firefly in a straight line in an open field; an enemy crosses it perpendicular to the line, crossing the minimum amount of fire to reach me.
Example 2: I cast Firefly across where an enemy is standing, and they move away from it immediately on their turn.
Example 3: I cast Firefly across where an enemy is standing, and they stay in it during their turn (to attack, use items, save AP, or they were knocked down or stunned).
Example 4: I cast Firefly to fill in a choke point between lava patches. An enemy has to cross several meters of fire to reach me.
The way the game works: example 1 does damage once. 2 does damage twice. 3 does damage once, plus once more for every turn that the enemy remains in fire. 4 does damage once per "step" taken.
The way it should work: example 1 and 2 should do damage once. 3 and 4 should do serious damage, based on time spent in fire.
I think it's important, tactically, that example 4 do far more damage than example 1. But you shouldn't be able to stand around in fire casually because it's only going to tick once per round.
could do an end of turn check that looks at current surface and previous surface.
if currently on surface x damage.
if previously on surface that same turn x damage.
i like the damage on movement and i think it should be severe and punishing. the current mechanic provides to much incentive to standing in one spot. i think you should be punished MORE for standing in it then moving. however the movement aspect still needs to be punishing enough that its not worth moving through said surface to attack an enemy. ie: lower the moving damage to much and it makes it to easy to just rush right through the surface and attack a mob making elemental surfaces trivial in the combat dynamic.
