Polyhedral dice, used for playing many tabletop roleplaying games (image credit: timepunching)
Tabletop roleplaying, as opposed to freeform online play-by-post. 
Wikipedia:Tabletop role-playing game
Characters
Mai Yamato originated as a Changeling: The Dreaming pooka, but changed greatly after that game ended.
Poltergeist is primarily a Marvel Universe RPG hero, although she does show up in journal roleplay every once in a blue moon.
Category: tabletop