Quake (series)/YMMV

Appliable to the series in general

 * Follow the Leader: Quake, with the antecedent of Doom, began the multiplayer experience in the 3D FPS genre, but Quake III Arena, along with its rival game Unreal Tournament, paved the way for the multiplayer FPS. 10 years later, it's still one of the biggest feuds in the gaming history.
 * In Name Only: Aside from II, IV and Enemy Territory, none of the games' "plots" have anything to do with each other. Indeed, ID originally wanted the "Strogg" arc to be an entirely new franchise, but ultimately decided the game needed the brand recognition which the "Quake" name would bring. (Also, their original idea for a franchise name was already copyrighted by someone else.) Quake III Arena's story makes an attempt to unite the different Id universes until that time into a single story arc.
 * Self-Plagiarism: The first game was pratically identical to Doom in gameplay and theme, with the only major difference being that it used true 3D instead of sprites. Quake II and III subverted this, the former by having a different theme, the later by focusing solely on the multiplayer aspect.

Appliable to Individual Games

 * Quake I
 * Quake II
 * Quake III Arena
 * Quake IV
 * Enemy Territory Quake Wars