- Fanfics in general fall into this - as is the case with professional authors. Many fanfic writers' earlier fanfics might not resemble their later fanfics in terms of plot or format. This is understandable as fanfic writers often get tips from reviewers on how to improve, and will often use them.
- Bird features this in the second arc. Most of arc two was rewritten from scratch when the author realized that severe structural errors had been made, resulting in a drastically different story to be told.
- Dr. Brainstorm's first few appearances in Calvin and Hobbes: The Series had him with unfocused gold eyes. He later gets Green Eyes (making him a Significant Greeneyed Redhead).
- In The Series, it starts out with rather mundane plots, and Calvin acted a lot more like he was in the original strip - a hyperactive little kid. Eventually, he became a much calmer Gadgeteer Genius (and even later on, The Chessmaster). He does get a brief Character Check in "Invasion" thanks to Laser-Guided Amnesia, though.
- In The Calvinverse as a whole, the earlier stories tend to be rather poorly written. It eventually starts improving by the point of Retro Chill. Swing123 considers his first two stories in the verse to be Old Shames, and has rewritten both of them (though he's more or less fine with the third installment).
- A big example in Child of the Storm, which started out as a light-hearted family fic with liberal sprinklings of humour - albeit with a warning from Word of God that it would get steadily darker - and one that emphasised the Harry Potter side of the crossover, the Marvel contribution being restricted to the MCU prior to Iron Man 3. Then, chapter 11 introduces HYDRA, their chief weapon, the Winter Soldier, and villainous Ensemble Dark Horse and Gravemoss. The story then shifts gears, steadily developing into a complex and intricately plotted Mega Crossover with a colossal Gambit Pile Up and a penchant for truly epic battles.
- Citadel of the Heart, as it's known today, is a Massively Multiplayer Crossover which functions similar to the author's own rendition of Kingdom Hearts as told with his own vision and ideas in mind. However, the first entry in the continuity, Truth and Ideals, started off as no such thing; it was a purely standalone Pokémon fanfic which was a whole other basket of worms in terms of Early Installment Weirdness, and there wasn't a remote hint as to the formation of the Citadel Of The Heart continuity until over 40 chapters into Truth and Ideals. Later entries into Citadel Of The Heart would later be far more blatant with the crossover elements.
- Enter Ken Finlayson: There are entries from Ken's journal which do not appear from later stories; Ken is stated to have been born in Leeville, Ontario instead of Casablanca, Morocco; Ken seeming to be actually crazy... Although that could just be a case of Character Development. There are also moments when Norrisville is stated as being in the state of New York, predating the revelation that Norrisville is located in some New England state.
- Friendship Is Magic: The Adventures of Spike: The Previously On segments at the beginning of each chapter, and the stylized scene breaks, were both dropped at reader command after the first few chapters.
- The original first few chapters of Hit List were less polished than the rest of the story and read like a straight-up High School A.U. with the Legend of Zelda cast, as opposed to later chapters treating the games as canonical precursors by having Link, Zelda, and Ganondorf as the reincarnations of the games' characters (the writing was fixed when the author did a rewrite). The sequel, From the Dust, uses more direct references to the games, with the characters getting magical items and entering actual scenarios from the games. This stands in contrast to Hit List, which kept everyone in the more realistic setting of a high school, had the characters make use of mundane items to defend themselves, put much less emphasis on interacting with plot elements from the games, and had no magic or past-life interactions until Link and Zelda fight Ganondorf.
- The Infinite Loops were codified by Saphroneth but made by Innortal. Thus, Innortal's loops will occasionally do things deemed impossible in later loops, which is usually Hand Waved by the fact that they were the first loops and the restrictions didn't exist yet.
- The Lone Traveler is by two different authors, and the transition was not seamless.
- The Lone Traveller became the Lone Traveler (i.e. switched from a British spelling to an American one)
- The Traveler goes from using meaningless names as aliases to Sue Donym's, pop culture references, and Character Name Aliases.
- A watch that synced to the local time whenever the Traveler moved on to a new universe disappeared.
- The particulars of the Traveler's backstory changed.
- A mysterious figure who appeared in the first story has disappeared entirely, never to be mentioned again.
- Saki After Story has this in its first chapter, even though there are only two as of this writing. In the first chapter, mahjong is seemingly treated as a two-player game (Saki and Teru face each othernote , with Saki winning 112,000 points to Teru's 110,000), and Saki and Nodoka are on a Last-Name Basis, as opposed to the First-Name Basis they adopted in the training camp between the prefecturals and the nationals, at the end of the first anime series.
- In the early chapters of Stroll, Octavia's monologues were shorter and the pacing was much faster. As the story developed and the author became more comfortable writing the setting and characters, the monologues became much more important to the story and the pacing evened out considerably.
- Fairly noticeable in The Vinyl And Octavia Series. The first story in the series is more or less a straight adventure story. Although there is comedy, the story itself is not one, unlike the rest of the series. There's no sexual tension between Vinyl and Octavia, and aside from a few mentionings of shipping, there is no hint that the two have feelings for one another. Finally, this story is around forty-thousand words long and spread out over multiple chapters, unlike the rest of the series, which are all one-shots (with the exception of Vinyl and Octavia Have Multiple Dates, but that's still only two chapters and is in fact shorter than some of the other stories).
Early Installment Weirdness /
aka: Fan Fic