World of Runes
Change things up
Every ability can be altered with "runes", a system totally new to Diablo 3. Runes come in every shape and size, and they can affect abilities in surprising ways. For example: Rain of Toads, a Witch Doctor skill that drowns enemies in falling toads with acidic blood, can be changed into a giant toad that swallows a monster and vomits up treasure.
"There's literally billions of character builds," Martens said. "That's kind of a big deal."