Environmental Effects are one of the Combat Systems in Divinity: Original Sin Enhanced Edition. The environment-based combat mechanic is one of the key features of the game that make it standout from the competition.
From Ground Surfaces to Clouds and Weather, the Environmental Effects on these can either make you or break you in a battle. As such, it becomes more important than ever to pay attention to your environment and try to use it to your advantage wherever possible.
Controlling the Environment
The environment in your combat-zone is dynamic and very much in play at all times during a battle.
Used a fire spell while you and your enemies were standing on Oil that you spilt by accidentally breaking open a barrel of oil earlier? ......Oops, now the whole room is on fire and you and your enemies alike are slowly burning to their death.....unless you cast a Rain spell and now the fire is out....BUT now you cannot see a thing because of all the Steam that resulted from this.
That is one example of the level dynamicity that Larian Studios has put into their game. Therefore it is important to think ahead and control your environment to avoid collateral damage where it can be avoided.
The Effects
You can control the environment through 3 mediums - Ground Surfaces, Clouds and Weather. Below is a list of the various Environmental Effects that you can create or find in each medium and how do they alter combat.
Ground Surfaces in Divinity: Original Sin Enhanced Edition can give rise to certain Environmental Effects. Below are the different types of Ground Surfaces available:
Ground Surfaces
Water
Created by breaking 
Water Barrels or using spells such as 
Rain
- Can be frozen to create Ice. Ice is slippery and can cause creatures to be
Knocked Down . If hit by fire, the ice will melt back into water. - Can be electrified by using Aerotheurge skills. All creatures standing in the water will become electrified and
Stunned . - Can be removed using
Tornado, and terrain affecting Pyrokinetic skills.
Fire
Created by using skills such as 
Burning Blaze, 
Firefly, 
Flare, 
Infectious Flame, 
Self-Immolation or 
Meteor Shower. It can also be crated by casting any Pyrokinetic skill on an oily surface.
- Causes
Burning status effect to any characters, enemies and objects on it. - Can be removed using Tornado or any terrain affecting Hydrosophist skill.
- Using a Hydrosophist skill will create a Steam Cloud over the area.
Lava
Created using 
Lava Core skill.
- Will kill/destroy anybody or anything that does not have 100% or more Fire Resistance.
- Cannot be put out but may be removed using Tornado.
Oil
Created by breaking an 
Oil Barrel or using skills like 
Midnight Oil.
- Causes
Slowed status effect to all characters in it. - Can be ignited using Pyrokinetic Skills or placing a burning object/character on the oil surface.
Ooze
Created using skills like Magical Poison Arrow or physically by hitting zombies.
- Causes
Poisoned status effect to any objects/characters in the surface. - Can be exploded by casing Pyrokinetic skills onto the surface.
Blood
Created using any skill that causes 
bleeding status effect.
- Piercing or Slashing damage from weapons can also create a blood surface.
- Can be frozen to create Ice. Ice is slippery and can cause creatures to be Knocked Down . If hit by fire, the ice will melt back into water.
- Can be electrified by using Aerotheurge skills. All creatures standing in the water will become electrified and Stunned .
- Can be removed using Tornado, and terrain affecting Hydrosophist skills.
