Table of Contents
Alternate History Clichés
Commonly abbreviated to AH Cliches (no accent on the e because we're a bunch of lazy francophobes), these describe certain concepts, technologies, events and scenarios that tend to crop up in a large number of timelines, particularly those written by those unfamiliar with the wider AH community. What follows is an alphabetical list of the most notorious clichés. As you can no doubt see, most of the clichés on the list have their own separate pages (which contain more info, with frequently tongue-in-cheek descriptions - just a precaution to keep you impatient readers interested 
).
Important note: Not all of the concepts or plots listed here are total clichés themselves ! While most are, many are just good ideas (e. g. a surviving independent British space/aviation industry), marred by the same old unresearched assumptions of AH authors. Others are tolerable (e. g. alternate Israels, the greater proliferation or survival of airships/battleships than in our history, etc.), but can easily be written badly or be overdone to the point of irrelevance… Or worse - making the reader bored.
A List of the Most Common AH Cliches
- Everybody loves eugenics: An easy, lazy way to paint an scenario as dystopic if one keeps butterflying real historical genocides and massacres away.
- Nazi Argentina: The idea that Argentina was crawling with Nazi sympathizers to the degree in which they could take power and join the Axis at any given moment just because the author says so.
- Pan-Slavist Romania: A common misconception is that Romanians are Slavic people and that they would want to join a Pan-Slavic movement of their neighbours.
- Pan-Turkic Tajikistan: Similar to the above, the misconception that Tajiks are Turks, where as in reality they are Persians.
- Pan-anything: While movements such as Pan-Arabism, Pan-Germanism and Pan-Slavism existed in OTL, that doesn't mean other, sometimes ridiculous varieties would have existed in ATL.
- Pendulum Fallacy: The idea that if a country/religion/ideology etc loses territory it has in OTL, it has to gain territory elsewhere to compensate.
- Pin the Zion on the Eurasia (Alternate Israels based in overly weird places)
- Random Axis South America: When a random South American nation joins the Axis, or goes Fascist during the 1930s. Related to the already mentioned “Argentina becomes an instant refuge for vengeful Nazis, who set up a Third Reich in exile” cliché.
- Space programme changes: Generally, absolutely any TL which involves any change at all to the OTL space programme will result in a vastly more extensive and successful one than OTL. Even if the change consists of Neil Armstrong wearing red socks instead of white on March 14th 1967.
AH.com discussions on alternate history clichés
The "Rules/Clichés of AH" thread (a.k.a. The Grand List of AH clichés)
Irritating clichés about pre-1900 alternate history
Irritating clichés about post-1900 alternate history
20th-21st century alternate history clichés
Alternate history clichés that annoy you
Things you dislike about alternate history
AH clichés that are inevitable and sometimes necessary
AH Cliches from Alternate Worlds - A fun DBWI take on the topic of alternate history cliches.
Allohistorical Convergence Pet Peeves - A thread critizing the Citroen DS Incident that often crops up in TLs, commonly leading to a lot of clichés.
AH Recurring Tropes, and the timelines that avert or subvert them