Invasion UAC is a megawad by David Bernardi (Xsnake), meant for ZDoom-based source ports. Containing 32 very large, difficult levels, aimed primarily at cooperative gameplay, but also supporting single player, Invasion UAC is set mainly in a series of UAC locales overrun by the forces of Hell, which also include some new monsters through DeHackEd. The WAD is notable for featuring infinite ammo, eliminating the need to scour for supplies and focusing purely on the combat for most of the map. Invasion UAC was originally released in 2005, as three-level wad, and new levels would be added to the project gradually, until a full 32 were reached in version 5, released in 2009. The latest version, iu-part5-zd109c.wad, dates to 2012.