Board game expansions allow new game strategies and are mostly based on the basic game. These games can only be played with the basic game. You have a game, you don't get enough and now there's an expansion to come. Depending on the expansion, it brings you new tasks, takes you further into the story or expands the number of players in the basic game. This extends the fun and enriches the game with new and interesting aspects. With some expansions, for example, new factions or new tasks are added.