It's a stereotype of gamers -- playing in their parent's basement. I've known of this stereotype pretty much all my gaming life, yet, perhaps ironically, I've never played a game in any basement. In fact, I'd only even been in a basement once before the age of 35. After the age of 35, I've only been in basements when house shopping.
In my part of the world (U.S. Southeast plains/coast), basements are very rare.

What is this "washing machine" you speak of?Wow they must be. Not being in a basement kind of boggles my mind, since that's where I keep the washing machine. Never gamed in one though.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.