World of Warcraft is a bad example of this. The client you have downloaded is always patched to the latest version, even if you haven't bought the expansions.

World of Warcraft is a bad example of this. The client you have downloaded is always patched to the latest version, even if you haven't bought the expansions. Each expansion unlocks content. So once you buy The Burning Crusade, you get access to the Outlands zone. That only matters if you have a character that's level 58 or higher. Blizzard redid the entirety of the Vanilla WoW experience in the Cataclysm expansion. Even if you did not buy that expansion, the level 1-60 are still the new content.