The joke is that the words "Priest" and "Wizard" in the 2023 game "Shadowdark" by Kelsey Dionne are used in the generic sense of "person that does the miracle stuff" and "person that does the merlin stuff", but autistic pedants insist those words to exclusively refer to level titles for "level 3 cleric" and "level 11 magic-user", respectively.
The joke isn't actually funny.