Liquidize105: I wondered what I'd come back to after taking the time to explain what it is.
Oh boy, I wasted my time. It's like talking to an ox, who thinks the first time he heard about a thing is when it started existing.
Thanks for the condescending tone, but your long description of the term was pretty much incomprehensible, and contradicted how some others in this thread explained the term.
For instance, you claim being a 1st person view game is one important ingredient of being an immersive sim, while someone else gave Ultima IV as an example of an immersive sim. Was he just being sarcastic, I wouldn't know. Some of the descriptions of "immersive sims" seem to fit e.g. Ultima 7 and Ultima Underworld quite well, where you can even bake bread ("combine flour with water, and put to oven") or make popcorn ("throw corn into a fireplace"), totally optional actions.
Someone else mentioned the most important aspect being having several approaches to obstacles. To me that sounds like most CRPGs, you usually have different approaches to problems if you are a warrior, wizard, hacker, thief etc. By that description, I agree that e.g. Portal is not an "immersive sim" even though it has a physics model where you can throw stuff and sometimes you might be able to solve a problem a bit differently than what the developer intended, but generally it is a pretty linear experience where it is clear developer has decided for you how you are supposed to advance in the game.
How about Far Cry 2 then? When you mentioned that you should be able to burn any wooden objects but not e.g. metal objects in an immersive sim, that certainly gave me flashbacks of playing Far Cry 2. I would burn trees, wooden huts, fields of dry grass, enemy cars, enemies etc. with the flamethrower, giving a pretty good impression of "if it can burn, it will burn".
It certainly also gave several ways to approach situations, e.g. if there was an enemy checkpoint ahead, you could try to speed through (not caring about enemy shooting at you), exit your vehicle and snipe the enemies at the checkpoint from afar, or even try to avoid going though the checkpoint, e.g. driving through a dense jungle instead. So, it is an immersive sim then, even the fact that it is indeed in first person? All checkboxes marked?
I've personally always described Far Cry 2 as a "non-linear first person view GTA-clone in Africa".
Well, maybe there is a Wikipedia article that explains the term better and in a comprehensive way, without contradicting itself.