Rain Weather = movement -1, but MP/HP regens,
and monsters glow/berserk. Nightime eyesglow.
Strong winds should enhance combat speed,
what am basically saying is that when the player or monster steps into each terrain type in GreedFall they should be able to feel the change, music alone wont do it, and running at the same speed won't be convincing. So in order to keep things feeling freesh you should add modifiyers that change how the player moves across towns, terrains, and during weather/combat, i noticed alot of games don't have this or use randomizations so things get really flat and repetitive, thats because the walking speed is the same through the whole game, and we know each tarrain is diffeernt from lookingat it, so changing action and combat all together by terrain would make the game more strategic for movement speed to enahnce each terrain.
you could pose a few must have treasure and quest/equipment in tough terrains that benefit the enemy more than the player such as a lake crocodile or sea monster, they should have an advantage when moving across water, but no on land, like they could recover HP in water, and move fast, but when they reach the land, they dont recover anymore.