When TV geeks and nerds talk about TV and films, sometimes they'll slip in little terms for common principals, laws, effects and other trivia. Some of these started out as industry terms others as Internet memes, and some have been coined by critics, but they are all now collectively considered 'TV Tropes'. Here is a simple list of the most common ones, though an entire, exhaustive database has been archived at the fantastic site TVtropes.org
The Stormtrooper Effect
This is the phenomenon that occurs in films with allegedly expert snipers, who it turns out can't hit a barn with a bazooka. Its named after the Stormtroopers from Star Wars, who are mentioned several times as expert marksmen, yet never seem to hit anything. My favourite example is in Behind Enemy Lines, where Owen Wilson is seemingly chased by the world's worst sniper
Redshirts
This is the name given to the ancillary character in a film or TV episode, whose only purpose is to get captured or killed. The character has no back story and usually isn't even afforded a name. The convention is named based on episodes of Star Trek The Original Series, where the random person who died was always in a red uniform. The best reference to this is found in Galaxy Quest, where Sam Rockwell's character is a red shirt who is generically called "Guy".
Chuck Cunningham Syndrome
character suddenly stops appearing without formally being written out of the show, and is never mentioned again. The term comes from the above scenario occurring to Ritchie Cunningham's brother on Happy Days. Film examples are less common, but check our Toby Wiseau's "The Room". In the second half, the alleged best friend simply vanishes
The Other Darrin
This is the act of replacing the actor who plays a character with someone entirely different, as if nothing has happened. It comes
from Dick York replacing Dick Sargent as Darrin in Bewitched, and other examples are littered everywhere from Sunset Beach to the much celebrated The Dark Knight
Jumping the Shark
Happy Days strikes again! Jumping the Shark comes from an episode in series five, where the Fonz is involved in doing a water ski jump over a live shark. It was originally used to describe when a program becomes ridiculous and unrealistic because the writers have run out of fresh ideas, but has since taken on a more general definition, as the point where a quality show stops being any good and starts sucking. Which brings us to...
Nuke the Fridge
This one comes from Indiana Jones and the Kingdom of the Crystal Skull, specifically the scene where Jones survives a nuclear explosion by hiding inside a refrigerator. In many respects it now replaces the original meaning of Jump the Shark, ie the point where a drama becomes too ludicrous and unrealistic to take seriously anymore
Hanging a Lantern/Lampshading
This is a relatively newer Hollywood term. When something in the plot is stupid, ridiculous or non-sensical, a character often mentions or draws attention to this very fact ie. they hang a lampshade on it. The idea is to let the audience know you're aware of the absurdity, everyone acknowledges it, has a laugh and moves on. Its pretty stupid, but surprisingly common. Lost used this a lot, and its used to comedic effect in the 200th episode of Stargate SG1
Mook Chivalry
This term is essentially the idea that when a group of bad guys attack, they do so one at a time. Its so common now, we almost don't notice, but it was spoofed brilliantly in Austin Powers. My main man Roger Ebert refers to it as the one-at-a-time attack rule
Inverse Ninja Law
The Inverse Ninja Law, along with Mook Chivalry and The Stormtrooper Effect, are collectively called the Principles of Evil Marksmanship.
The Inverse Ninja Law is, generically speaking, the term used to explain how allegedly skilled and trained Ninjas, or indeed other warriors, are actually terrible in combat and easily defeated. The larger a group of these advanced and skilled warriors is, the more rubbish they become, serving as little more than cannon fodder. A good example is the hordes of secret warriors in The Mummy
