In many academic systems, introductory courses for a field of study are designated "101". That the course is "100-level" indicates that it is intended for beginning or first-year students. That the course is numbered "101" (or occasionally "100") indicates that it is the first such course.
Many subjects actually taught will have at least one 100-level course, especially in fiction. The ones that don't are usually specialized subjects. Occasionally, a fictional 101 course will be way more or less advanced than the course number justifies. Not infrequently 101 will be the only class level ever mentioned. Its ubiquity even allows a character to mark himself as a university student or professor by mentioning (Subject) 101.
The notation of a course as 101 means that it is expected that anyone with normal intelligence and work ethic and minimal talent in the field can successfully complete it, and will thereby acquire the basics of the discipline; also, that anyone with the basics of the discipline will know any fact labeled "subject 101". This connotation leads to the common subtrope "Arcana 101", in which a writer tries to give an accessible flavor to some exotic discipline through introducing it by means of a (usually fictional) 101 course. The sarcastic variant is "Inanity 101", in which the 101 course is in some subject for which it would be unreasonable to expect training to be necessary or useful. The trope title falls more or less under this variant.
Due to Eagleland Osmosis, "(Subject) 101" is often used by non-Americans who have no idea where the phrase comes from — though some British universities have adopted the system, and it is used in Australia.
Not to be confused with Always in Class One (the equivalent would be the earliest offering of the week for (Subject) 101), the trope Room 101 (no matter how much you might hate the class), or the TV series Room 101 (which is named after the former where people send their hates into said room, which, yes, could be these classes.)
- Remembrance of the Fallen mentions two 100-level courses, Romulan 111 and WEP 125 ("Principles of Electronic Countermeasures"), but Eleya is also taking a class designated CMD 305.
- In the DC Super Hero Girls fic Super Villain Prevention 101, heroes-in-training who have the potential of becoming villains, or are former villains, have Super Villain Prevention 101 as a class.
- Most of courses are numbered in The Official Fanfiction University of Middle-earth:
"OFUM offers a wide range of subjects as diverse as Evil Is as Evil Does 101 taught by the esteemed Sauron himself and Poetry 202 with highly acclaimed author of 'Merry Dol and Dong Dillo: How to keep your neighbours out'; the one and only Tom Bombadil."
- At the beginning of Teenage Mutant Ninja Turtles (1990), Casey Jones offers to school Raphael in "Pain, 101" after Raph's interference allowed two purse-snatching lowlives to escape him (though, it should be said, without the purse).
- In Fantastic Four (2005):
- After Doom traps Mr. Fantastic with liquid nitrogen and a chair:
Doom: Chemistry 101: What happens to rubber when supercooled?
- With an Ironic Echo in the final battle, when the Thing cracks open a fire hydrant towards the flaming Doom:
Mr. Fantastic: Chem 101. What happens when you rapidly cool hot metal?
- After Doom traps Mr. Fantastic with liquid nitrogen and a chair:
- In Devon Monk's Magic in the Blood, Business Magic 101 was one course she took. It didn't help with the matter at hand.
- In Seanan McGuire's Velveteen vs. universe, Heroing 101. An extremely far ranging course.
- In Lois McMaster Bujold's Falling Free, Leo Graf is trying to take over a space station, by organizing a bunch of kids.
Revolution 101 for the Bewildered, Leo decided grimly, should be his course title.
Or worse 050: Remedial Revolution...
- Community has every episode named after a college course (or something that would sound like a college course). "Spanish 101" and "Debate 109" have both been episode titles.
- Criminal Minds has an episode called "Profiling 101", where the BAU speaks in front of a college class.
- In Heroes, Hiro describes Daphne's attempting to get him and Ando to fight each other as Villainy 101.
- How I Met Your Mother did this in the 5th season opener, having Ted teaching Architecture 101.
- On Law & Order once Serena Southerlyn asked Arthur Branch if some maneuvering he had done was part of "Trial Tricks 102." The implication was clearly that, while he may have been slightly clever, she still didn't have a lot of respect for his methods.
- The short-lived 1988 CBS show TV 101 was about a television production class taught in a high school. The cast had, among others, Matt Le Blanc, Stacy Dash and Teri Polo.
- Zoey 101 is titled after this fashion. Additionally, one episode has Quinn alluding to this trope, when she reasons that Chase insistently going out with a crude Zoey-lookalike is him trying to replace her, then concluding "That's Psychology 101!".
- Tim Daggett, gymnastics commentator for NBC, has an oft-repeated catchphrase, "Gymnastics 101: Fly high and stick the landing!" (He's repeated it so often his fellow commentators have teased him about it.)
- The videogame Spellcasting 101: Sorcerers Get All The Girls.
- Its sequels are appropriately titled Spellcasting 201 and 301.
- The battle tutorial in Paper Mario: The Thousand-Year Door is called "Action Commands 101"
- Wizard 101 is named for it — the game is about going to a school to learn to be a wizard.
- There's an old shareware game called Tubes that names its Idiosyncratic Difficulty Levels in this manner. The easiest is Tubes 101, the hardest is Tubes 301.
- My Little Pony: Friendship Is Magic had the reference book "Slumber 101: Everything you wanted to know about slumber parties, but were afraid to ask" in the episode Look Before You Sleep.
- Spongebob Squarepants episode "Artist Unknown" features Squidward teaching Art Class 101.
- The Simpsons had Nuclear Physics 101. In one episode, Homer reveals that he never passed "Remedial Science 1A".
- "Go back to Feminism 101" is more or less the feminist blog equivalent of "lurk moar." (There is a webpage titled Feminism 101 but the use of the term "Feminism 101" predates the page.)
- LittleKuriboh did a skit called "Dan Green presents Abridging 101", which was using loads of sarcasm and Verbal Irony to show us how not to do an abridged series (although he was guilty of a few of those points himself).
- The lonelygirl15 episode "Interrogation 101".
- The Redearth88 video "Creepy Stalking 101".
- In Red vs. Blue, when Tucker tries to teach the alien how to speak English, he refers to his 'class' as "English 101: Remedial Kickass".
- It aren't that hard.
- The Webcomic Demonology101.
- For a while, the web version of Girl Genius was separated into two parts, respectively titled "Girl Genius 101" (starting with the first issue) and "Girl Genius Advanced Class" (starting with where the print comics were at the time). When 101 caught up with the start of the Advanced section, they were merged.
- The Half-Life 2 parody webcomic Concerned had "Anticitizen 101", as a pun on the game chapter "Anticitizen One". The course is on how to act as a rebel in the City 17 uprising, and the first lesson is about apologizing to Gordon Freeman whenever one gets in his way.
- The Webcomic Sorcery 101.
- In the Order of the Stick book "Dungeon Crawling Fools", Roy retorts against Belkar's accusations of being Dumb Muscle by pointing out that he has an MBA from a Fighter's College. When asked what was taught, Roy grudgingly admits to having attended "Standing In Front Of Other People 101".
- His sister Julia first appears going to her "Necromancy 101" course.
- The Dreamland Chronicles: Dan recommends Nobility 101.
- School Bites has Blood Drinking 101.
- Sonichu has DAT 303, Dating Education. It's Exactly What It Says on the Tin.
- Schlock Mercenary, "Officer Training 101" according to Legs: Don't taunt Murphy.
- El Goonish Shive has Generic Science 101 (on the blackboard and partially hidden by the speech bubbles).
- :Nuclear Warfare 101.
- Norwich University, a University in Vermont, has an open house named "NU101."
- UCSD, and presumably the rest of the University of California system, averts this trope. Lower division classes are all in double digits, and at the time, there are no lower classes that are Subject 101.
- True. At UC Berkeley, Subject 1-99 classes are lower division, Subject 100199 are upper division, and Subject 200-299 are for graduate students. There are other numbers as well, for various other specialized courses. Sometimes things can get weird: Math 16A covers the same basic material as Math 1A, but is meant for non-math/science majors and is thus easier. Likewise, Psychology 2 is easier than Psychology 1, since 2 is meant for non-psych majors. The real kicker? Statistics has three lower division courses (2 (for non-math/science/business majors), 20 (for math/science majors), and 21 (for business majors)), none of which are actually required for the Statistics major.
- Interestingly enough, the labeling appears to be semi-random. One major requires people to take Math 1A/1B, then Math 53/54. Other majors require Math 16A/16B (which is easier) instead of 1A/1B. And crosslisted classes often don't share the same number with themselves, leading to courses such as "MCBC100A/ChemC130A".
- Similarly, at Penn State, if you want an easy course, Subject 101 is not what you're looking for. A number of departments have Subject 001, which is as introductory as a class will ever get.
- At Indiana University, 100-level classes in many subjects are intended for non-majors. Majors start their classes in the 200-level.
- The Mexican version of this trope is simply using one single number, usually Roman in official designation. The first calculus class, for example, would be Calculus I, then Calculus II, then Calculus III and so on.
- Universities in Brazil do the same.
- As do Chilean ones. Might be a Latin American thing.
- In the US, these often combine with 101; hence MATH101 is Calculus I.
- To clarify, in these sorts of cases American History I might be HIS 101, followed by American History II aka HIS 102, while World History I might be HIS 106, followed by World History II aka HIS 107. (There may or may not be HIS 103, 104, and/or 105.) They are all introductory classes, thus 100 level, but (in my experience) the 10 numbering really doesn't indicate much else. The main point is arranging things so that when classes are listed by course number, sequential classes are listed together, starting with the first in the sequence.
- That's exactly how it goes in Chilean ones; for example, General Physics go FIS100 (introduction), 110 (General I), 120 (General II), etc., all of them, of course, according to the college in question.
- At University of New Hampshire, first year classes are 401 and 402, second year 501 and 502, etc. Nobody seems to know why.
- Some schools attempt to subvert this trope and appear more edumacated by adding a '0' to the end of the three digit designation, thus giving the regular course a higher number—and, by supposed extension, make it seem more advanced. English 101 becomes English 1010, for example. This fools no one, though it occasionally confuses the person in charge of transferring credits at a school who numbers things normally.
- One Cal State school uses 1008 and 1009 in place of 100 and 101, possibly to accommodate more class numbers.
- In an attempt to confuse new students familiar with this trope, or possibly to give more room for sub-divisions and differentiate materials done for old courses, some British universities use a four digit code, often with a department tag. Introductory Mathematics might be MT 1001, whilst Organic and Biological Chemistry 1 might be CH 1601.
- A similar concept is in use at some colleges in America. For example, Texas Woman's University, all classes are assigned a four digit code after the subject clarifier. The first number is the level, the last number is how many credit hours it offers, and the middle two define the class. As such, a lot of classes start at 1013, with labs being marked as 1011.
- Georgia Tech uses four digit course numbers for everything, but there's no pattern in the last three digits. An introductory class might be 1050, or 1100, or 1113, or even 1371.
- At Canada's Trent University it varies by department (generally three digits in humanities like English and Women's Studies, and four digits in the actual and alleged sciences).
- At Texas A&M University, first year courses are 1xx, second year 2xx, third year 3xx, fourth year 4xx, and grad school 6xx. Presumably the Aggies didn't like 5xx.