- Actor Allusion: This isn't Tony Jay's first time voicing a Big Good who happens to be the leader of an organization that deals with espionage and is known only by his occupation.
- Development Hell: The film adaptation. Cult director Roger Avary was tapped to write and direct, then was sent to jail for vehicular manslaughter. When he got out, the funding had dried up. Supposedly he's still attached, but few people really want to fund a video game movie in the age of comic book movies.
- Hey, It's That Sound!:
- The Grenade Launcher sound from Quake II and Quake III: Arena is reused once again, for the hand grenades.
- Enemy Territory reuses the sound assets from RTCW, including the music.
- The zombies' growls and shrieks were previously used for the undead creatures in The Elder Scrolls II: Daggerfall, which in turn lifted the sounds from old Hanna-Barbera cartoons, most notably Scooby-Doo.
- The benevolent wizard in the intro who seals away Heinrich grunts in pain exactly like the Doomguy.
- Manual Misprint: The game's manual claims that Castle Wolfenstein was released for the Apple II in 1983 and was about infiltrating a Nazi headquarters to assassinate Adolf Hitler with a bomb. Castle Wolfenstein was released for that system in 1981, and the plot described was actually that of its sequel Beyond Castle Wolfenstein from 1984.
- Milestone Celebration: RTCW was released twenty years after Castle Wolfenstein, the first game in the Wolfenstein series.
- Playing Against Type: Tony Jay, known for playing sinister villains, does the voice of the OSA Director.
- What Could Have Been: Originally, Wolfenstein: Enemy Territory would have been a sequel towards RTCW. Only the multiplayer portion of the game made the cut, as a free downloadable game, with the single-player portion of the game being cut. This paved the way for the Enemy Territory series which continued with Enemy Territory: Quake Wars.
Trivia / Return to Castle Wolfenstein