Because prisons ban Dungeons & Dragons.
Prison officials instigated the Dungeons & Dragons ban among concerns that playing the game promoted gang-related activity and was a threat to security.
Yeah, it might inspire them to carve a magic wand out of a bar of soap, and pew-pew prison guards with magic missiles.
Hey, can we get prisons to ban religion because it similarly promotes fantasy thinking and organizes people into groups, aka “gangs”? Bible study could be a gateway to organized crime, you know.