An addition to the MovieOS (though this has declined in recent years as directors and actors become more technology savvy) anything on a computer can be done by banging away on the keyboard for approximately 1-2 seconds, even if said action is drawing a picture or searching the hard drive.
Seen in: Revenge of the Nerds, Jurassic Park, countless others
Bugetary Law of Female Competency
A female character’s ability to engage in self-preservational activities is directly proportional to the budget of the film.
In an ultra-low budget cheapie, a woman will stand, facing the monster/slasher as he/it slowly advances toward her and scream. The woman is, of course stabbed, devoured or impregnated with an alien embryo.
In mid-range budget movies, the woman will scream and run away, usually breaking a heel (all women in these movies wear high heels). She stands about a 50/50 chance of escaping. If she gets away, is usually because she is rescued by a male character.
In a big budget action flick, the woman, usually played by Sigourney Weaver, will open up a can of whup-ass on the offending villian/monster/horny alien.
Examples: bottom end budget, Breeders Top end, Alien and sequels.
The latest edition includes several of my contributions.
When I get to make my big-budget 'splosion thriller, it will have a scene like this:
Heroes find bomb with big red (it has to be red) digital countdown display
Heroes work frantically to defuse bomb
Timer ticks down toward zero
Tension builds
3… 2… 1… zero
Heroes squint eyes shut–
Pause
They look again at the bomb
One guys says, “Hmmm,” pokes around
Pulls readout off bomb in one piece
Other guy says: “Did it malfunction?”
First guy: “No, it was never attached.”
Other guy: “So that wasn’t the timer?”
First guy: “Guess not.”
Other guy: “So we actually have no idea how long we have.”
First guy: “Apparently.”
Other guy: “Oh.”
Pause
And back to the bomb, working as fast as possible
That or eject the ammunition/magazine from the firearm and throw it off a cliff somewhere. Not terribly hard to do with a basic knowledge of firearms.
Collary: After/during said party, the teens will pair off and go off into some isolated area to have sex/go skinny dipping, thus making it incredibly easy for them to be slaughtered one by one without the rest knowing.
Selective Tanker Contents
In any action film, the contents of any tanker truck are determined by the subcategory of “action movie” in which it appears. There is a 90% chance that if this truck is shown in the foreground of a shot it will explode/rupture at some point in the film.
Action-action: Gasoline, liquid nitrogen, napalm
Action-comedy: Sewage, milk, glue
Action-political drama: oil (from a business owned by a corrupt politician), toxic waste, experimental disease (less likely to explode)
The Bogart Ratio
Characters who smoke will be seen lighting ten cigarettes for every one cigarette they are seen stubbing out or throwing away.
sightings: Casablanca, The Big Sleep, High Fidelity
The Knight Boat Principal
In any movie or TV show that revolves around a unique, high-tech piece of equipment–whether it be a talking car, a giant robot, or ghost elimination devices–the protagonists will always be faced with situations that are solvable using that piece of equipment. Named for a scene in the Simpsons where Homer, Lisa, and Bart are watching a show called Knight Boat, which is similar to Knight Rider but with a talking boat instead of a car. When the bad guys fleeing Knight Boat take the sensible step of leaving the water for the land, Knight Boat notices a canal that runs parallel to their escape route. Lisa says “There’s ALWAYS a canal!”
Sightings: Ghostbusters, Big O, etc. etc.
which leads us to
The Ubiquity of Giant Robots
In anime and many Japanese films, such as the Godzilla movies, giant robots are cheap, effective, and so easy to manufacture and maintain that everybody who is anybody has one.
which brings us to
The Anime Improvement Corrolary
Everything is better if you add a giant robot.
The World Is a Parking Lot
In the event of an emergency, it is OK for the main character to park wherever they want without consequences or police interference. For example: the curb, the middle of the road, on a sidewalk, on the neighbor’s lawn, etc.
There’s a great quote, I don’t know who said it: “To the guy who only has a hammer, every problem looks like a nail.”
Human Waste Recycling System
Nobody ever needs to go to the bathroom.
It is now fairly well established that if you are, say, a movie hero being attacked by several bad guys, and they are in helicopters while you are on the ground, and they are firing at you with the sorts of machine guns that spray a squillion bullets a second, you can survive by using the rather brilliant tactic of running a bit quickly and ducking every now and then. When will real-life soldiers learn to adopt this incomparably brilliant strategy?
Cites: the Die Hards and other Willis vehicles, most action movies, most Bond movies
If you are going through a bit of a bad patch, and are feeling angry about things and having a bit of a tantrum, clearly the most natural way to express this is to approach the nearest horizontal surface on which numerous objects are neatly arrayed (e.g. a fully-laden table, sideboard or laboratory bench) and swipe along it with your arm in a rather brusque fashion, sending the objects crashing to the floor. Even though no-one has ever seen anyone do this in real life.
Cites: more or less any emotional ‘drama’ ever brought to the silver screen
I must speak while typing
Whenever a movie character is typing, they are irresistably compelled to speak along as they type, while sitting alone in their rooms.
Ex: Wargames, Sleepless in Seattle.
Vietnam Soundtrack
No scene taking place in VietNam shall be without a classic rock song playing in the background, preferably by The Doors, Credence or Hendrix.
Get that steering column fixed!
Every movie car has 10 times the amount of play in the steering wheel than a normal car, requiring constant overcorrection.
Hubcap regeneration
If a hubcap happens to come off during a movie chase, it regenerates.
Ex: Bullitt, Striking Distance, Planes, Trains and Automobiles, every episode of CHiPs.
No immediate sightings for this – it has been too long, but memory tells me this is true:
Show Us Your Tits and Die
Found in slasher or generic horror movies. First woman to bare her breasts ends up dead – usually seconds after revealing her glorious Boob Job.
**
THE SEXY HITMAN
Professional assassins are the most considerate, sensitive, and most desirable lovers.
Used in: anything by Robert Ludlum, Species, The Langoliers, many other examples…
The optical regenerative powers of surprise
If a character wears eyeglasses, and he sees something that is shocking or unexpected, he will take off his glasses to get a better look.
Ex: almost anything starring Jeff Goldblum
** The Doppleganger principle **
If a hero or group of heros belong to a specialized group the major villian will share the same skills or have once been part of taht organization and have gone bad. The Villain should never have a different skill set. If you are an ex commando with partatrooper training and proficient with the sword, your nemisis will have been in your same unit, and sword class but went evil.
Sightings: SWAT Numerous Urban War films.
The ultra-classic Bullit car chase also features the incredible self-repairing headlight!
The ultra-classic Bullit car chase also features the incredible self-repairing headlight! 
Galaxy Quest did a nice job of spoofing these.
“The counter always went down to the last second on the show!”