Early Installment Weirdness/Tabletop Games


 * Magic the Gathering has this in spades. The game's original setting was much closer to a Standard Fantasy Setting. (In fact, the first set, Alpha was a deliberate attempt to cram as much familiar fantasy elements in one set.) The cards frames looked different and were continually updated until finally being given a complete makeover. The colors were much less defined mechanically than today - many cards did things that would be unacceptable in their colors today. The rules were messy. There were bizarre mechanics like flipping cards over in the air, dividing creatures into two different groups that can't ever meet, camouflaging creatures, subgames and playing for ante. Rules text was written in a much less formal style, the ultimate example of this probably being Rock Hydra. Also, some early cards also referred to abilities as "special powers." And finally, the "Block system" of one large set followed by two related sets, as we know it today, didn't actually begin until Mirage. Homelands was originally shoehorned into an Ice Age "block", but then later made Coldsnap to properly complete the Ice Age "block".
 * Warhammer 40000 was initially just Warhammer Fantasy Recycled in Space with things like the Eldar being explicitly called "Space Elves". Also Warhammer Fantasy Role Play, the role-playing game spinoff of the wargame, wasn't renewed for some fifteen or twenty years, thereby preserving a lot of early canon (like several never-seen-again races, or the Slann being the Precursors themselves) in places where the WFRP was popular.
 * Of particular note is the fact that in its earliest incarnation 40k was more than a little campy and silly at times, whereas now the setting is famous for being a Darker and Edgier Crapsack Universe. Among the fandom, First Edition Warhammer 40k is usually only considered canon from a Broad Strokes point of view since large portions of its background information is no longer compatible with the current 40k universe.
 * Dungeons and Dragons in its earliest incarnations included things that would confound players of later editions, such as a Level Cap and limited class selection based on race, the Exceptional Strength rule where Warrior classes (e.g. Fighter) could have a strength "between" 18 and 19 (18/59, for example), and Armor Class getting better as it got lower. If the ancient "Blue Book" were shown to a player who picked up the game after the mid-nineties, most of it wouldn't make sense. Generally, First and Second Editions are fairly similar, while 3.0 and 4th Edition were both radical departures from what came before. Some people like the old weirdness; each change has had caused the Unpleasable Fanbase to adopt every attitude conceivable from quitting the game to playing with 30 year old books to eagerly embracing every new rule as soon as it's published.
 * In addition, third and fourth edition are part of the Advanced Dungeons & Dragons series, not the original series that was titled "Dungeons & Dragons," which was discontinued entirely. The original "Dungeons & Dragons" was very different, especially since players were expected to use the rules from the Chainmaille wargame, while d20 was just a fast alternative for people that lacked the Chainmaille rulebook.