EverQuest, or EQ, is an online fantasy game known for helping to popularize Massively Multiplayer Online Games. It also helped promote the economic value of online games when, in 2001, economist Edward Castronova estimated that it had the equivalent of a GDP between Russia and Bulgaria. Gameplay elements include quests, class roles and leveling, crafting, and Player versus Environment combat with optional Player versus Player combat. There are 17 optional expansion packs for EverQuest.