In The Day of Sigma, the Hunter Base is located in Abel City. In Mega Man X2 it appears briefly during X's conversations with Dr. Cain. In Mega Man X3 it is located in Dopple Town and is attacked by Dr. Doppler's forces in the beginning of the game, being the Opening Stage. It is later revisited for cutscenes.
From Mega Man X4 to X6 the base appears as the stage select screen. In Mega Man X5 Dynamo attacks the base, and the battles against him also takes place inside it. Mega Man X7 features the base during most of its cutscenes, and Mega Man X8 has it as the stage select screen just like its PlayStation predecessors. In that game it also appears at the R&D Lab option menu, as well as during Sigma's reveal cutscene.
In Mega Man Xtreme, the Hunter Base's Mother Computer is hacked and all of its data is overwritten, and the resulting fake data has sent the whole world spiraling into chaos.
Rockman X manga series
The Maverick Hunter Base was heavily damaged when Sigma became a Maverick. A Neo Maverick Hunter Base is built in Doppel Town in the Rockman X3 manga.
- Mega Man X is the only numbered game not to show any glimpse of the Hunter Base, which was compensated on its remake.