A Mythology Gag is a sort of Meta-Continuity Nod, wherein a reference to some facet of a show's mythology or past production history (which is not always considered Canon in the context of the show) is made. This trope is usually taken largely as a bit of gratuitous humor, since if the program you're watching is "real" then the characters shouldn't be thinking in terms of any continuity, alternate or otherwise. (Sometimes this will be hilariously lampshaded by the characters, who wonder how they could possibly know such a thing. Also, the Celebrity Paradox might come into play.)
Often seen in Revivals, Reboots or Series Franchises, when an element from the previous version of the show (or from the previous show in the Series Franchise) is referenced or seen in some way. This is usually done as an acknowledgment to the fans of the first incarnation of the show. When successful, serves as a reassurance to those fans that the producers aren't trying to disrespect the original source material. When unsuccessful, only reminds fans that the original source material essentially never happened. The success of the Mythology Gag is always a matter of opinion.
See Remake Cameo for when the Mythology Gag involves actors from the original production. Compare to: Continuity Nod, Discontinuity Nod, Recurring Element, I Want You to Meet an Old Friend of Mine, Actor Allusion, Continuity Cameo, Company Cross References, Ascended Meme, Meet Your Early Installment Weirdness (when taken a step further) and Shout-Out. Contrast Development Gag, which references things that would have been part of the work but were left out halfway through production, and Early-Bird Cameo.
Example subpages:
- Anime & Manga
- Card Games
- Comic Books
- Fan Works
- Films — Animation
- Films — Live-Action
- Literature
- Live-Action TV
- Music
- Pinball
- Radio
- Tabletop Games
- Theatre
- Toys
- Video Games
- Web Original
- Webcomics
- Western Animation
Other examples:
- The Sistine Chapel, the physical building itself, has the same dimensions (40.9 meters long by 13.4 meters wide) as the Temple of Solomon does in The Bible. This reinforces one of the main theses of the Chapel: to demonstrate that the Christian tradition flows directly from the teachings of Judaism.
- Albeit briefly, Animated Inanimate Battle pulled one off in the show's intro. As a nod to its pilot episode, Brain and Bouncy Ball can be seen playing poker, with the same Early Installment Weirdness that can be seen in the pilot.
