If you ever watch a movie with me, you'll quickly notice that I get very engrossed with the plot and emotionally affected/involved with the story/characters etc.
Recently I watched two films in the theatres: Project X (which I didn't really like) and The Hunger Games (which I enjoyed). While one movie is set hypothetically in the 'real' world of Pasadena, CA, and the other is set in a dystopian future world, the second is the one that I find less difficult to believe. The Hunger Games was a relatively well shot movie, had a good plot (I haven't read the book yet, but hope to, eventually), and was predictable in many ways but was honestly pleasant to watch, in that I could easily identify with the characters and, well there was even a moment where I screamed… so yeah. I totally recommend this film!
Now if you want to watch Project X (which I don't necessarily recommend) I think you might want to stop reading here, but while this movie is supposedly based in reality here are some of the qualms I have with it:
2. Pasadena, CA is not the average High School location
3. These are movie high school students so they're not actually high school aged, most look too good (and those who don't are there for a reason).
4. Did I mention that it didn't need a flame thrower?
5. Generally you cannot jump off the roof of a house into a backyard pool or onto a bouncy castle and expect not to be hurt.
6. Hiding 1000s of people in the backyard of a house to avoid police attention does not tend to work.
7. 12-year-olds generally do not acquire tazers easily.
8. College kids don't generally find attending a high school party cool.
9. Mixing drugs and alcohol in those quantities likely results in negative consequences
10. Most goth kids can't get away with murdering their parents and living on their own (I hope!)
11. One great party does not make a geek into a cool kid.
12. One crazy party is unlikely to bankrupt parents who are THAT rich (the level of wealth in the home seems too large for the family not to have insurance etc.).
13. Driving a car into a pool would likely dirty the pool more (among other issues)
14. A fire damaged (see comments re: flame thrower) mini-van is not likely to be immediately driveable or road safe.
15. It takes longer than one day to successfully invite 1000s of people to a party for that same evening and have them successfully arrive! Even with txting and social media etc.!
16. I like to think people wouldn't just put a short guy in an oven… I mean really, so what if he's a dwarf in stature, this seems unusually cruel to me… nor does he seem to be the right age and demographic at the party…
17. Did I mention that the movie really didn't need a flame thrower?
Anyway, my point really is that plausibility really depends on context: in The Hunger Games we are led to believe that this is a far future society that is structured very differently and has very different social mores and whatnot. In Project X we are supposed to believe that this is just a normal high school party gone completely out of control, but evidently this is hard to believe (see previous comments).