The expansion pack, Galactic Civilizations II: Dark Avatar, was originally designed to add new units, new maps, a new story-based campaign, user-created opponents, an epic generator, espionage agents, asteroid fields, new diplomatic treaties, unique planet environments and much more. However, Stardock decided to expand on the already impressive feature set based on fan feedback and suggestions. In addition to the original concept, new features now include a streamlined technology tree, Mega Events, super abilities that are unique to each civilization, a visual makeover, more advanced opponent-design features and more.