There are the good guys, and there are the bad guys. Both groups are named. Now you would expect these names to be diverse, right?
Nope. If one name is an acronym, the other is too. If one name is one word, the other is too. If one is referred to thematically (such as by color, e.g. "the Reds"), the other's name will match it ("the Blues"). This is Unified Naming System. This seems weird but is probably the best way to express there's something between those two. The more cynical (and/or Doylist) could also say that the reason for this is the author's lack of imagination.
Political parties in real life and fiction like to do this a lot too. Can be justified if both sides adopted names that were selected by a common third party, or if we're just hearing one side's nickname for the other.
- The Justice League faced off against the "Injustice League".
- The Legion of Superheroes regularly fought the Legion of Supervillains.
- "Alpha Flight" was the senior of three Canadian supersquads; "Beta Flight" and "Gamma Flight" were basically trainees. In the first issue of the comic book, the junior flights were shut down, with the most promising members being promoted to Alpha; several of the rejects were then recruited into a villainous "Omega Flight".
- SpyBoy: The two rival spy organisations are S.H.I.R.T.S. (Secret Headquarters, International Reconnaissance, Tactics, and Spies) and S.K.I.N.S. (Supreme Killing Institute).
- S.H.I.E.L.D. (Strategic Homeland Intervention, Enforcement and Logistics Division) vs. AIM (Advanced Idea Mechanics) and HYDRA (as in the mythological creature). SHIELD's spinoff organizations also qualify, having names such as STRIKE, SWORD, ARMOR, and HAMMER.
- Our Man Flint. Z.O.W.I.E. (Zonal Organization World Intelligence Espionage) vs. GALAXY. (Or rather, evidently, just "Galaxy".)
- From Gulliver's Travels, there's the Big Endians and the Little Endians.
- Which actually refer to the reason for the conflict: how to eat eggs.
- The plethora of acronymous - and mutually acrimonious - competing groups in Illuminatus!. This is not done entirely seriously - witness KCUF - Knights of Christ United in Faith. Or WHORE - White Heroes Opposing Red Extremism.
- The Children of the Light oppose the darkfriends (and really anyone who looks at them funny) in The Wheel of Time.
- The various government departments in Keith Laumer's Retief series: "Manpower Untilization Department, Directorate of Libraries & Education", "Motorized Equipment Depot, Division of Loans & Exchanges", "Special Committee for the Reconstruction of Underdeveloped Nations' Economies", etc. (MUDDLE, MEDDLE, SCROUNGE)
- Get Smart: CONTROL vs KAOS.
- Lancelot Link, Secret Chimp. APE (Agency to Prevent Evil) vs. CHUMP (Criminal Headquarters for Underworld Master Plan).
- The Man From Uncle. UNCLE (United Network Command for Law and Enforcement) vs. THRUSH (Technological Hierarchy for the Removal of Undesirables and the Subjugation of Humanity).
- Maybe, maybe not. The "expansion" of "THRUSH" was never used in any of the series episodes, but appears only in several Expanded Universe UNCLE novels.
- Nebulous has K.E.N.T. and L.O.U.G.H.B.O.R.O.U.G.H. - both being named after British universities.
- Champions: UNTIL (United Nations Tribunal on International Law) vs. VIPER (Venomous Imperial Party of the Eternal Reptile or Victory In Perpetuity through Eternal Resolve).
- A.C.E. Agents has ACE (Alpha Command Echeleon) vs. PYTHON (...actually, nobody knows, including its leaders. They just thought it was a good name for an organisation to take over the world)
- Team Fortress 2: Builders League United vs Reliable Excavation and Demolition.
- Grand Theft Auto: San Andreas: Grove Street Families vs. Kilo Street Ballaz vs. Varrio Los Aztecas vs. Los Santos Vagos.
- INTERPOL vs V.I.L.E. in the Carmen Sandiego franchise.
- The Advance Wars series have a double example: Orange Star, Blue Moon, Green Earth, Yellow Comet and Black Hole are named for both colours and astronomical objects.
- U.N.I.T.Y vs H.A.R.M in No One Lives Forever 1 & 2.
- The SCP Foundation deals with so many other groups competing for anomalous objects they listed them all on a page for editors' reference. Of them, several are mainly referred to by their acronyms: the Global Occult Coalition (GOC), the Office For The Reclamation of Islamic Artifacts (ORIA) and the Unusual Incidents Unit (UIU) of the FBI.
- Another group of renegade artists known as "Are We Cool Yet?" is usually referred to by OOC editors as AWCY(?).
- DuckTales (1987): The D.I.A. (Duckburg Intelligence Agency) goes up against F.O.W.L. (Foreign Organization for World Larceny)
- Darkwing Duck: SHUSH (name so top secret none know what the acronym stands for) against F.O.W.L. (Fiendish Organization for World Larceny). Yep, F.O.W.L. got a slight name change in the transition from show to show.
- M.A.S.K.: MASK (Mobile Armoured Strike Kommand) vs. VENOM (Vicious Evil Network Of Mayhem).
- King Arthur & the Knights of Justice: On the hero side there's the Knights of Justice and on the villain side there's the Warlords, who in "A Knight's Quest" are fully known as the Warlords of Evil. In the comic adaptation, the latter also goes by the name Warriors of Vulcan's Forge, switching which of the two is the matching word (Justice vs Evil; Knights vs Warriors).
- World War II: Allies vs Axis.
- The Cold War: U.S.A. vs. U.S.S.R.
- Another Cold War related one: Capitalism vs. Communism.
- More Real Life: Triple Alliance vs Triple Entente.
- The North Atlantic Treaty Organisation (NATO) vs. the Warsaw Treaty Organisation (WTO), another name for the Warsaw Pact.
- The Russian Revolution: The Reds vs. the Whites.
- And prior to that the Bolsheviks vs. the Mensheviks. Though those words come from terms meaning "Majority" and "Minority" respectively (based on which side they took in a particular crucial vote).
- In early Christian church history, two groups arose over what word best expressed the relationship between God the Father and Jesus Christ in their creeds: the homoousians (those who favored "of the same substance") and the homoiousians (those who favored "of similar substance"). Yet another group didn't really see the point to all this arguing and called themselves the homoians (a deliberately vague compromise best translated as "alike"). For the record, the first group ultimately got their way.
- Rival college fraternities and sorority names will often have a similar number of seemingly random Greek letters, making them indistinguishable from each other to non-college students or anyone who just doesn't care about Greek life.
- SPOON vs FORKS vs KNIVES vs PLATTER.
I predict we will see a new contender trump them all and make PLATE.But then we'd have a Lensman Arms Race, with the creation of GLASS, TABLE, or even *gasp* KITCHEN!
- At which time DEN, BEDROOM and ATTIC will make their appearance, followed by HOUSE (except that they're just fans of Hugh Laurie and only joined in the fight because it looked like fun).
- Well, if they can't stand the heat...
- Bah, they'll all be crushed to dirt once the Kombined Initialism Takeover Crusade Holistic Enforcement Network: Strike Insertion Neo-Kommando forces rise up.