The concept of the game revolves around the aftermath of mankind's first contact with space aliens. In this case, since all the aliens come from One World Orders, they quickly become fascinated with Earth's cultural diversity. So much so, that sending your kids to high school on Earth becomes the next big thing. Naturally, with all those teenage aliens running around mingling with the locals and getting into Zany Schemes, Hilarity Ensues.
The game was based on comedy anime (particularly Urusei Yatsura), with maybe a dash of western shows like Galaxy High, but was originally released in the '80s when anime was still a pretty niche thing. So, it was written as a general comedic sci-fi RPG. After anime started becoming mainstream in the mid-90's, the game was reworked to make the anime influences the main selling point.
The game came in three editions: 1987, 1989, and 1997. The only difference is each successive version added another alien powers table, and different sample characters in each edition (with a lot of overlap)
The books also come with a list of adventure seeds called "Episodes", many of them based on the plots of episodes of real comedy anime.
This game provides examples of:
- Amusing Injuries: Since it's a comedy RPG, no matter what sort of calamity befalls your character, the most that will happen is they lose a Bonk point or two, and get taken out of action temporarily if they lose all their Bonk points.
- Animesque: The illustrations for the rulebook in the 1997 edition are the most heavily anime-inspired.
- Bag of Holding:
- The 4th dimensional purse, which holds six times its apparent capacity by using a miniature time machine to put your items into six different time zones.
- Also the Warpspace Overnight Bag (can hold dozens of outfits in a 1x1 tote bag, but only holds clothes) and the Black Hole Storage Closet upgrade for vehicles (can hold absolutely anything, as long as you can fit it through the trunk door.)
- Black Widow: According to the sample adventure, Nookians carbon-freeze their husbands after the wedding night.
- Breast Plate: The Battle Bikini item.
- Captain Ersatz:
- Class Trip: The "Field Trip" adventure starts with a class trip to the observatory, and (TFOS being TFOS) ends with a game-show battle for the fate of the Earth.
- Clingy Jealous Girl: Rami, and an inordinate number of plots provided by the game call for one.
- Distressed Damsel: A distressing amount of plots involve this.
- Drill Sergeant Nasty: The vice principal is described like this.
- Earth Is the Center of the Universe
- Easy Sex Change: The Boy/Girl Gun and Boy/Girl/Boy power cause characters to change biological sex in an instant.
- Evil Twin: Episode 5 involves one of the player characters being visited by their tasteless, lecherous cousin who looks exactly like them.
- Exactly What It Says on the Tin: The game is about teenagers (or at least people who behave like stereotypical teenagers) from outer space.
- Fishing Minigame: The "Anglers from Planet X" supplement, released as an April Fools joke in 2020. Because, as a Japanese-inspired RPG, an overly-complicated fishing minigame is obligatory.
- Flight: A possible superpower for aliens.
- Freaky Friday: The Personality Swappers.
- Gender Bender: The Boy/Girl Gun and the Ranma ½-inspired power "Boy/Girl/Boy" in the 3rd edition.
- God Guise and Sufficiently Advanced Alien: Subverted. The assorted aliens have strange and mysterious powers which generally put them into superhuman territory. Sure, the humans get stuff like "rich", "smart", typical high school social survival traits, but how do you hold out against an alien "jock" who can bench a tank? Oh wait... humans also get the Human Fake Out. Since the aliens consider Earth to be the Coolest Place in the Universe, most of them will believe practically anything a human says. Which makes encounters with the Green-Skinned Space Babe very interesting when you explain that going to second base is a common human greeting among good friends on their own....
- This was a fan-made expansion that gave some more "bizarro" powers to humans, to all GMs to add elements of series like old Mecha animes, Ranma ½ and Project A-ko to their campaigns. These included powers like Girl/Guy/Girl Trigger (contact with a specific stimulus caused the character to be affected as though hit by a Boy/Girl Gun, a Genderbender Transformation Ray), Own a Big Mecha (the character has a piloted robot or super battlesuit made by one of their relatives- which meant they'd get ticked if it got damage) and a human version of the Monster Out power.
- Gone Horribly Right: If you roll too high on a skill check, the GM may rule that something hilariously unfortunate and inconvenient happens.
- Hyperspace Mallet: One of the items in the game is the Hyperdimensional Hammer, a large melee weapon that comes with a button-sized device that can store it in an extra-dimensional pocket and summon it again at will.
- He Who Must Not Be Seen: The principal. The gamebook says to run them by having the guilty PC step into their office, then stepping back out again, remembering nothing about what happened, but quivering in fear and terrified at the idea of ever facing that again.
- Hit Points: Or more specifically Bonk points. Pretty standard, except a) you don't die if you run out, and b) you can lose them by being humiliated as well as getting hurt.
- Hulking Out: The "Monster Out" ability causes alien characters to turn into giant, ferocious monsters when agitated.
- Humans Are Special: Due to their cultural diversity, humans are considered the coolest beings in the universe, to the point that they can Fake Out aliens with claims like "plaid bellbottoms are cool" or "kissing is a perfectly acceptable way to say hello".
- Interrupted Intimacy: It's a rule. If two characters try to have sex, a hilarious interruption must ensue, because sex scenes aren't as funny as people trying to get some intimate time alone.
- Imported Alien Phlebotinum: Available cheap just about everywhere.
- Mega Neko: Episode 8 involves a giant cat adopting one of the PCs as its own kitten.
- The Men in Black: The Alien Control Officers are there to deal with aliens who cause too much trouble.
- Non-Combat EXP: The game works on a voting method: the other players at a session make secret votes to decide if a player gets 1, 2 or 3 XP. The average is rewarded.
- No Such Thing as Alien Pop Culture: Pop Culture is Humanity's Hat, and the reason why so many Aliens are interested in the place.
- Puny Earthlings: Aliens get all kinds of cool powers; humans can have more mundane 'powers' like connections to important people or loads and loads of money.
- Transformation Ray: Aside from the Boy/Girl gun, there's also Featherface's chicken gun.
- Many to Urusei Yatsura, among others. The first two things on the alien powers list are flight and shooting lightning just like Lum's, even.
- "TFOS Does Winterfest" introduced an idea they called "Out of Control Power" where some external stimulus switches on one of the player's abilities, and one of the examples was being hit with cold water. Maybe a coincidence, but considering whose work inspired this game in the first place...
- Sliding Scale of Anthropomorphism - The various alien races are given a rough sorting based on how closely they resemble a human form (and how likely they are to send scientists scurrying to the nearest bomb shelter). Near Humans are perfect examples of Human Aliens and the Green-Skinned Space Babe. Not Very Near Humans are defined by having a roughly humanoid form and nature: Rubber-Forehead Aliens, Intelligent Gerbils, Little Green Men and The Greys. Real Weirdies are anything else; Starfish Aliens are most common examples, with Insectoid Aliens also possible, but theoretically a Real Weirdy could also be an Eldritch Abomination or even from a race of Energy Beings.
- Space Police: The Benzmen
- World of Ham: Downright encouraged in the game's rules. "Great Moments In Overacting" are specifically mentioned."Something underwater on an alien planet has just grabbed your foot. If you aren't screaming like a cat dipped in Nair, you aren't grasping the seriousness of the situation."