LARP stands for Live Action Role Play, and involves participants taking on characters from canon and acting out game play in the real world.
LARPing in Supernatural
- 4.18 The Monster at the End of This Book - The comic book shop guy mistakes Sam and Dean for LARPers.
- 5.09 The Real Ghostbusters - Demian and Barnes and the other fans at the Supernatural convention take part in a LARP.
- 8.11 LARP and the Real Girl - Moondoor is Michigan's largest LARPing game. Described on its website as "A world of intrigue, honor, passion. Four kingdoms – followers of the Moon, Elves, Warriors of yesteryear, and the dreaded Shadow Orcs." Charlie Bradbury is the Queen of Moondoor. After solving the mystery of who was killing members of the game, Sam and Dean join in the Battle of the Kingdoms as a way of having fun.
- Live action role-playing game - definition on Wikipedia