It can be hard, describing tabletop gaming to someone who isn't familiar with the pastime. Dungeons and Dragons has made it into the common culture now, I think, but you still encounter the occasional nonpractitioner who associates it with the thick-glasses-and-pocket-protectors "nerd" stereotypes from twenty years ago... or worse, the occasional religious paranoiac who associates it with devil worship, child sacrifice, and heavy metal. I remember once, years ago, when my Mom asked what I did on weekends (at a time when I was gaming with a group that used homebrew systems and custom settings almost exclusively), my explanation boiled down to "yelling about numbers".

I have since decided that the best way to describe tabletop roleplaying to a non-player is as follows:

"Okay, you know the show 'Whose Line Is It Anyway?'? Sure, the American one with Drew Carey, whatever. Okay, well, imagine that, but instead of short comedy bits, it's one long ongoing action-adventure story. And you still have one guy behind the desk who describes what's going on and assigning points, but instead of pulling suggestions out of a hat or polling the audience, you have dice. And the points do matter for something. That's about it.

No, we don't televise it. No, you generally don't have to get up and be each other's hands. No, there's... we have rules for that. Yes, we do occasionally have musical numbers, but it's not generally encouraged. And there's pizza. Usually."