Our D&D/Gaming friend John immediately came to mind when this design came up on TeeFury. I also gave one to my sensei Lester as a Christmas present.
The joke has many geeky levels, no pun intended. Firstly there’s the worn-out punchline from the Dead Alewives comedy bit about a typical group of so-called devil worshippers. Secondly, the design is derived from the old AD&D 2nd Edition logo which was on every rulebook from 1989 to 2000. Lastly, John often played wizards exclusively when he joined and he took an approach of playing them like the wizard from the Gauntlet video game. (That’s my opinion and it’s not meant as a dig. Besides, I haven’t played in three years and John has characters from other classes nowadays.)
Both recipients enjoyed these shirts and didn’t see them as insults.