- All-Star Cast: While making the first Gabriel Knight, everyone at Sierra probably stopped working when Mark Hamill, Tim Curry, Michael Dorn, Mary Kay Bergman, Jim Cummings, Jeff Bennett, Efrem Zimbalist Jr and so many other stars stopped by their office to record their lines.
- Fake Nationality: Just about everyone in the tour group in GK3, apart from Mosely, Lady Howard and Estelle.
- Genre-Killer: The infamous "cat hair mustache" puzzle in Gabriel Knight 3 is cited by Old Man Murray as one for adventure games as a whole.
- Name's the Same: Gabriel's benefactor in the third game is called James Stewart.
- The Other Darrin: Dean Erickson replaces Tim Curry as Gabriel in The Beast Within. Curry returned for the 3rd game. Jason Victor takes over the role in the remake.
- Unlike Gabriel, Grace has been played by a different actor in every game: Leah Remini in the original, Joanne Takahashi in the live action Beast Within, Charity James in Blood of the Sacred, and Cissy Jones in the remake.
- None of the original voice actors reprised their roles in the 20th anniversary remake, due to the original audio quality being too poor to salvage, and concerns that the actors (now several decades older than the characters) would no longer sound convincingly like twenty- or thirty-somethings. Plus, it probably would have been far too expensive for a small studio to hire A-list voice talent.
- Playing Against Type: Tim "Too scary to play the fucking Joker" Curry is the hero? And Mark "Actually played the fucking Joker" Hamill is the Bumbling Sidekick?
- What Could Have Been: Each game in the series had story or gameplay elements that never made it into the final product:
- Sins Of The Fathers was originally designed with a playable segment as Gunter Ritter in Colonial America.
- The Beast Within was likewise planned to have a playable segment as King Ludwig. In the finished game, said segment instead appears as a psychic dream of Gabriel's, as a cutscene only.
- The motorcycle in Blood of the Sacred, Blood of the Damned was supposed to be driven in a first person perspective. An arcade-style sequence where Gabriel escapes the Night Visitors, who pursue him as swarms of bats, was also planned, but eventually scrapped.
- Accessing SIDNEY in Blood of the Sacred, Blood of the Damned gives you a lot of seemingly irrelevant information about hauntings in Scotland, which Word of God has confirmed was intended as a teaser for the fourth game. After it became apparent that GK4 wasn't going to get funding, Jensen apparently briefly considered turning her material into a novel. Needless to say, fully twenty years on neither a game nor a novel has appeared yet, and though GK4 is still officially on Jane Jensen's to-do list, there's no telling when or if it'll happen at this point.
Trivia / Gabriel Knight