Stand-alone Expansion Packs
Some expansion packs do not require the original game in order to use the new content, as is the case with Half-Life: Blue Shift or Sonic & Knuckles. In some cases, a standalone expansion such as Heroes of Might and Magic III: The Shadow of Death, or Dungeon Siege: Legends of Aranna includes the original game. Standalone expansions are preferred by game retailers since they require less shelf space and are generally easier to move since they don't carry the prerequisite of owning the original game. Often, enhanced games or anthologies released as "Game of the Year edition", "Director's Cut", etc. are examples of standalone expansions. In some standalone packs if someone does not have the original or previous expansion packs, then they can't use certain units or races contained in the other games in multiplayer.
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