The 42-year-old actor started dabbling in Dungeons & Dragons when he was 10, but never lost his love of the game. Manganiello is so into the fantasy role-playing game that he recently built a full-on dungeon in the home he shares with wife Sofia Vergara -- and now he's sharing it with others.
"Just about everyone in Hollywood -- director, actor, writer, producer -- we all grew up playing Dungeons & Dragons," he said. "I built a dungeon in the basement of my house in Beverly Hills, and everybody comes over to my house to play."
"It was supposed to be the wine cellar, and suddenly when the months started to happen... he has these gigantic dragon heads hanging from the wall," Vergara hilariously confirmed during a visit to Late Night With Seth Meyers. "I love being part of it by organizing the room, giving him food there... cheese crackers."
Manganiello, a Pittsburgh native, was happy to share his latest D&D adventure with his brother, Nick. The pair donated games and books to kids at the Children's Hospital of Pittsburgh, and spent several hours teaching the kids how to play.
"At the heart of this game, it's about being able to step out of reality for a little while," the actor -- who is working on a Dungeons & Dragons movie script -- said. "It's about being able to step out of reality for a little while."
"I think it's so important because it allows the kids to be kids while they're going through these medical issues that are forcing them not to be kids, to be grown-ups," he added.
Manganiello isn't the only one using his star power for good. See more on how celebs are giving back in the video below.