Larianisms:
- heavy emphasis on ground surface effects and various interactions with such
- high prevalence of special throwable items and arrows that cause elemental effects for both PCs and NPCs
- high prevalence of barrels in the environment which can be broken open to cause special effects
- heavy emphasis on gaining high ground in combat for both PCs and NPCs
- significant emphasis on moving and interacting with objects as a means of problem solving and battle strategy in lieu of using characters' actual abilities
- alteration of a few spells and abilities to conform more to the principles listed above
D&D-ness:
-everything else in the game
You are, of course, aware that elemental arrows predate Larian, and were predominate in early adaptations of D&D games? I was running through BG the other night, a fresh new game in the EE, and got an explosive arrow as a drop. The real kicker, that arrow was a drop from the same encounter in the base game. Explosive barrels, et al, have been a thing forever as well, and Grease was a thing, all the way back in BG/BG 2 forward, and probably a lot of the other D&D based games in that era that I never got around to playing. That to indicate environmental effects aren't a "Larianism", they've been around a long time.
Interacting with the rest of the environment goes all the way back to Table Top. Players could climb stuff, jump over stuff, if they had the scores for it, light oil slicks on fire, use Entangle spells to control enemies, or party members... Jumping on stuff has been a thing in PC games for longer than Larian's been making games too.
