The 10 best DOS add-on games

This is an authorized add-on pack for Duke Nukem 3D.

Aftershock for Quake is an unofficial add-on for Quake.

Shub-Niggurath and her minions have been defeated, but that doesn't mean that Quake's forces are finished.

An unofficial add-on for Quake (like Shrak for Quake), Abyss of Pandemonium cheekily positions itself as the next part of the story, following on from Quake's official mission packs: Quake's fearsome general, the Dark Reaver Legond returns from conquering another dimension in the name of her master, to find out that a single human has repeatedly defeated Quake's minions.

This is an add-on episode for Duke Nukem 3D.Aliens have captured the President!

Duke Nukem's Penthouse Paradise is an official add-on level for Duke Nukem 3D, available exclusively from GT Interactive and Penthouse Magazine.

An original Quake add-on, Dissolution of Eternity sets out to expand upon the Quake universe by adding something fresh, while preserving the basic concept of the game.

Dimensions of the Past is an expansion to Quake and requires the original version to play.

You are the Avatar, returning to Britannia after 200 years of absence.

Tremor for Quake is the follow-up to Head Games' Aftershock for Quake.