KOTS

All monsters will always go through all damaging fields (fire, poison, energy fields).
If monster does have the required flag (eg. canWalkOnEnergy to walk on energy), then it tries to pathfind through that field, ignoring its damage completely.
If monster dos not have the required flag:
If there is a path that does not require the monster to walk through that field, monster will ALWAYS choose that path
In other case (path to target is blocked by field) then:
If monster isnt being attacked, then it will just wander
If monster is attacked, then it acivates "rambo mode" that enables all canWalk flags (fire, energy, poison)