An expansion pack is an addition to an existing role-playing game, board game or video game. These add-ons usually add new game areas, weapons, objects, and/or an extended storyline to a complete and already released game. While board game expansions are typically designed by the original creator, video game developers sometimes contract out development of the expansion pack to third-party company, or it may choose to develop the expansion itself. Board games and RPGs have been marketing expansions since at least the early 1970s.
The Zoo Tycoon series had six expansions.
Zoo Tycoon Expansions
Zoo Tycoon: Complete Collection included the main game, its two expansions, and some new content all in one pack.
Zoo Tycoon 2 Expansions
Zoo Tycoon 2: Dino Danger Pack was a download that included four dinosaurs and a new campaign. Because Extinct Animals included updated versions of these creatures, the pack was discontinued.
Zoo Tycoon 2: Zookeeper Collection was released on October 17, 2006. It was a pack that included Zoo Tycoon 2, Endangered Species, and African Animals.
Zoo Tycoon 2: Ultimate Collection was released on September 30, 2008. It includes Zoo Tycoon 2 and its four expansion packs.