Add-on

Add-ons or expansions (also called expansion packs) are content created for games that is released separately from the main game release. Downloadable content (DLC) is a specific form of add-on distributed through the Internet.

Fallout 3
The first game in the Fallout series to feature downloadable content was Fallout 3. With a total of 5 add-on packs released: • Operation: Anchorage • The Pitt • Broken Steel • Point Lookout • Mothership Zeta

Fallout: New Vegas
Fallout: New Vegas also features add-ons, with a current total of 4 pre-order bonuses and three add-on packs released as of July 19, 2011, with one more (Lonesome Road, release date not yet announced) to come: • Dead Money • Honest Hearts • Old World Blues • Lonesome Road