there are plans for Diablo IV or an MMO, if the Diablo game goes the route seen with WarCraft III / World ofWarCraft.WarCraft III and its expansion Frozen Throne introduced the new lore that would set the groundwork for the MMO quests, rich characters and locations.Diablo III will heavily use material such as characters, plots and locations not only from the original Diablo game and Diablo II, but