Dungeons and Dragons co-creator Gary Gygax has died. At first blush, this seems more like a Nerd World topic, and Lev Grossman doffs his +2 Cloak of Protection to Gygax over there. But I couldn’t let the news go unnoted here, because far from being a hermetic obsession of antisocial geeks, D&D had a wide influence on pop culture, even, …