Anarchy Online: Alien Invasion is the third expansion for the online role playing game Anarchy Online. Guilds are able to build their own cities, something that will draw Aliens who want to destroy the city and everyone in it. During those attacks, which strength depend on how many guild members are online, players basically have to survive two attack waves. After that, a small group can start a counterattack and get beamed on a space ship. Here they have to defeat the alien general in a time limit. When successful, they can expect new powerful items and special "alien experience points" which unlock new abilities.
While this expansion is aimed at high-level players, it also adds a starting area for new players and other new content, e.g. more quests and a reworked trading interface.