Making a TV show is a terrible grind — especially back in the day, when shows were entirely made up of standalone episodes. So it's no wonder that so many classic shows reached for the same handful of plots, over and over. Here are 12 storylines you'll find in every old science fiction and fantasy show.
1) The Female-Dominated Society
The idea of a society in which women wield the power (usually to terrifying effect, almost always while sporting exciting hairstyles/headdresses) was a big winner in writing rooms for several decades. Examples include Star Trek: TNG's"Angel One;" originally intended as commentary on Apartheid, Blake's 7's "Power;" Doctor Who's Drahvins; Space: 1999's "Devil's Planet" (don't pull any punches on the name there, guys); and Buck Rogers in the 25th Century's "Planet of the Amazon Women."
2) The Groundhog Day Episode
This is such a common episode that we've already done a roundup on it. The Twilight Zone did an especially upsetting version of it (of course, doing especially upsetting versions of things is really the show's forte) in "Death Ship," where some astronauts land on a planet, find a crashed ship that looks exactly like theirs, figure out that they're actually dead, and then...do it all over again. And again. Forever.
3) A Trip Inside The Mind
What's even scarier than evil aliens? The human mind, of course (plus the human mind is also much cheaper to film). Star Trek hits this one fairly frequently: TNG has "Dark Page," where Deanna Troi must journey into her mother's mind, and "Phantasms," where the crew watches Data's dreams in the holodeck; and DS9 has "Extreme Measures," where Bashir and O'Brien enter Sloan's mind after he's killed himself during an interrogation.
4)Your Worst Fears, Come to Life
This episode, in which something causes the cast's worst fears to come to life, has enjoyed continued popularity for many decades. The writers of Doctor Who, for example, have long been fans: "The Mind of Evil" has an alien parasite who causes people to see their worst fears; the more recent "The God Complex" has a scary hotel in which people find rooms containing their worst fears; and there are even some non-TV Who stories that include the idea. Other shows that have visited the same well include the X-Files ("X-Cops"), Buffy the Vampire Slayer (several), Supernatural ("Plucky Pennywhistle's Magical Menagerie"), and The 4400 ("Fear Itself").
5)Honey I Shrunk the _______
Say what you will about this story idea, the fact remains that there is nothing cuter than that teeny tiny runabout buzzing around the Defiant in DS9's "One Little Ship." There was also a whole segment in 1976's The Krofft Supershow called Dr. Shrinker, which was basically exactly what it sounds like (mad scientist + shrink ray + plucky children). Doctor Who has also used this a number of times, along with shows like Eureka ("O Little Town"), Farscape ("I Shrink, Therefore I Am"), and, in a delightful spoof version, Futurama ("Parasites Lost").
6) The Alien Society That Sure Looks a Lot Like the Romans
Listen, not every show can feature a time-traveling alien in a stylish blue box, but that doesn't mean other science fiction shows don't want their own crack at the Romans. Or whatever famous civilization or era (there is that Star Trek:TOS episode with a culture based on 1920's Chicago gangsters). But Romans are such a biggie that they've already gotten their own article here: Star Trek has both TOS's "Bread and Circuses" and the Romulans (who were specifically modeled after the Romans), Doctor Who has the comics series "Doctor Who and the Iron Legion," and, tragically, we just barely missed a Futurama version that also included centaurs.
7) The Trial
Oh no! Our heroes have accidentally violated a bizarre or unjust alien law, or the aliens are sick of humanity's nonsense, or maybe someone has made a false accusation! Seriously, I have no idea why the Federation doesn't require away teams to have full briefs on local law before doing anything.
Sometimes (almost all the time) the courtroom episode is a grand-standing mess designed to reduce the lawyers in the audience to tears. The biggest repeat offender is Star Trek, but it's a hard episode for TV shows to resist: Blackadder, Farscape, Battlestar Galactica, several Stargate's, Red Dwarf, Hercules... well, just imagine a show. It's probably had one. One of the most famous is, of course, Doctor Who's "Trial of a Time Lord," featuring the Valeyard.
8) There's a Duel, or a Ritual Fight to the Death
It's hard not to think of this as the "Shindig" episode, but it has a lengthy history that long predates Firefly. Star Trek:TOS has several versions: "The Squire of Gothos," "Arena," and "Amok Time," in which the contest is between Kirk and Spock, Blake's 7 has the appropriately titled "Duel," and Doctor Who had "The Curse of Peladon." There's an Outer Limits version where two humans have to battle arena-style against two aliens for the survival of humanity, there's a Buck Rogers in the 25th Century version...basically it's an oldie but a goodie.
9) Die Hard On A Spaceship... Or Wherever
The bad guys have taken over the spaceship, and the good guys have to steal it back. Usually this episode involves someone crawling through some kind of ventilation shaft. One notable example is "Rascals," that Star Trek:TNG episode that everybody hates where Picard, Ro, Guinan, and Keiko get turned into children and then Ferengi take over the Enterprise and the not-kids save the day, but really this is roughly every fifth episode of some seasons of Star Trek, and most other science fiction shows have gotten in on the action at some point.
10) The Most Dangerous Game
People are fun to hunt. This must be true, because television tells me so, over and over and over again. Sometimes they're bred to be hunted, sometimes they're imprinted to be hunted, and sometimes they're hunted because of environmentalism, but however it happens, it's always a good time.
11)The Body Swap
You can't learn the episode's lesson until you've walked a mile in someone else's body. The Whedon shows are big fans of this device, and shows from Supernatural to Eureka to Farscape have one or two episodes using it. A particularly notable version, though, is The Prisoner's "Do Not Forsake Me Oh My Darling," in which the writers had to figure out a way to get around Patrick McGoohan's absence (he was filming Ice Station Zebra). Their solution was to have Number 6's mind put into another body for almost the entire episode, so that they barely needed to use McGoohan.
12) Everybody Is Under the Influence of a Crazy Thing/Virus
You know, that episode of TNG where Tasha and Data hook up. Star Trek uses this one a lot: examples include TOS's "The Naked Time," (the original version of "Naked Now,") where a contagion makes people act crazy and causes Sulu to run around shirtless while wielding a foil; and TNG's "The Game," where everybody on the Enterprise falls under the spell of a game that's also a mind-control device. Also see: The Librarians, Warehouse 13.