RPGs (Role Playing Games) come in different forms. Books/Tabletop, IRC, pBem, Boards/Groups are the most commonly known formats.

Books/Tabletop - Role playing books are made for the game and help set you up for 'table top', which is being at a physical location with other people (most times) and using the books as a guide to create characters and play in a plot. These mainly use dice to determine outcomes.

IRC - Internet Relay Chat. This is when a group of people join a chat room as the character they will be playing, and all follow the lead of the 'GM' (Game Master, which is also who leads most other role playing games unless otherwise decided by the group of people), and play the character's role within the given plot. They range in time from an hour on up to when everyone just says good night.

pBem - Play by email. That is when a group of people, each taking on a character to play, will play their part in a type of round robin format through email clients, their posts being saved by someone chosen in the group or on a list specifically designed to save posts. This is a sister format and pretty much a twin to Boards/Groups.

Boards/Groups - using Invision or like boards to post in a round robin or tag format (tag=when someone 'points' to another character to being the one that answers the post that was just made), or using such groups as Yahoo, Google or like medium to do the same



Links to some Supernatural RPGs: (add your link below if you have a quality rpg you think fellow fans would like)

Margaret Weis Productions - Supernatural RPG Gamebook

Supernatural the RPG, AU

Supernatural Unforgiven - Season 4 RPG

Unexpected Crossroad - a crossover between Supernatural and The Vampire Diaries