Quake II: Ground Zero (also known as Quake II Mission Pack: Ground Zero), developed by Rogue Entertainment and published by Activision, is the second official expansion pack to the first-person shooter video game Quake II, following the release of Quake II Mission Pack: The Reckoning, developed by Xatrix Entertainment and published by Activision, on May 31, 1998. It was released on August 31, 1998 for Microsoft Windows. The expansion adds new content including single-player and multiplayer maps as well as various gameplay items. Quake II: Ground Zero received slightly above average to mixed reviews from critics, citing the expansion as being too similar to the original game.