Play-by-email

Play-by-email is a variant of RPG where the participants write down the moves of their characters through e-mail.

Pros

 * Players need not to be active at the same time
 * A game of this type can be set up for the fraction of the cost other types of gaming can represent

Cons

 * The game can be quite hard to follow, especially when the game has been active for a long period of time
 * The game can take a toll on one's mailbox, since one can receive a large quantity of e-mails for the game

Play-by-email games

 * Star Trek: Borderlands