- The in-and-out of Anarki and Slash. Their backstories tie them up together. One of Anarki's accessories in his default costume is a gift from her, even custom-painted, and one of Slash's head accessories is a pair of sunglasses belonging to him.
- The fact that the entirety of Id's history is represented in the game in a way or another. Even strongly disliked games such as Quake IV (weapon skins for the Nailgun and the Lightning Gun), Doom 3 (the entirety of the "Doom Marine" costume for Doom, which is filled to the brim with references to that game), Wolfenstein (2009) (several Lore Codex entries for B.J. reference the events of this game) and even Enemy Territory: Quake Wars (with the presence of Strogg & Peeker, based on the Strogg Infiltrator class) have a place in this game.
- The Expansion Packs for the games are also included in these shout outs! Strogg & Peeker's lore codexes include mentions to Quake II: The Reckoning's Gekk enemy, and the Fall 2020 update for the game added the Plasma Beam from Quake II: Ground Zero as an alternative skin for the Lightning Gun under the name "Incinerator".
Heartwarming / Quake Champions