A continuity is a fictional universe or timeline that is characterized by recurring characters and settings and an internal consistency with regards to characterization and depicted events.
G.I. Joe stories have been depicted in many comics and several animated series. Unlike Hasbro's other equal mega-franchise Transformers, G.I. Joe has more or less maintained a sort of continuation that stretches from the first series.
Much of the differences in G.I. Joe continuity depends largely on which medium it existed. At this time, the primary continuity families of G.I. Joe are its toy line, the comics and animated series. Each medium bring with it its own sub-continuities.
- Adventure - America's Movable Fighting Man, Adventure Team
- RAH - A Real American Hero, Real American Hero Collection, G.I. Joe vs. Cobra
- Extreme - Sgt. Savage and his Screaming Eagles, Extreme
- Sigma 6
Each of the continuities in the toy line are tangentially connected. RAH is meant to be a complete reboot of the G.I. Joe franchise but has since incorporated the original G.I. Joe character from the Adventure series. The video that came with the Sgt. Savage toys reveals Sgt. Savage being revived by RAH characters. The Extreme series, while another reboot of the G.I. Joe series, incorporates Sgt. Savage into its cast.
The comics represent the one long continuity despite jumping from one publisher to another. Devil's Due continues the storylines from Marvel Comics. While working primarily with the original Real American Hero concept, Devil's Due incorporated select characters from the other G.I. Joe toy series.
- RAH animated: Sunbow series and DiC series
- Spy Troops, Valor vs. Venom direct-to-video movies
- Sigma 6 animated series
The Sunbow series and DiC series are meant to be one single continuity, though the latter decided to retcon, revamp or ignore elements of the former.
The Sigma 6 animated series contains references to the direct-to-video movies but contains many revamps that question their connection.