Impressions for Diablo III beta up to patch 12. For those who are new to the Diablo series, Diablo III is a fast paced dungeon crawler RPG created by Blizzard Entertainment, Inc. It is the third installment of the series that continues with the story of the battle between good and evil. Compared to Diablo and Diablo II, there are a wide range of new features, classes, and monsters. Whether or not you’re a Diablo veteran, you’re in for a treat.