Civilization IV, a game so addictive it has its own support group, joins GameTap this week as the 1000th title on the service. Civ IV, under lead designer Soren Johnson (who is currently trying to make a game out of Spore), was the Civilization game that brought an incredible amount of accessibility to the epic franchise. Whether Civ IV expansion packs, Warlords or Beyond the Sword, are integrated into this version for the GameTap service is unknown, but perhaps they'll be added at a later date. For GameTap subscribers who have even the slightest hint of interest in an accessible strategy game and somehow missed Civ IV, along with Sid Meier's Pirates! which was made available a couple weeks ago, now is the time to try them on the service.