User summary:
Silverdawn was a heroic fantasy role playing game played my mail.
Players choose a character class from among a list of usual (and some unusual) types of characters, and were sent a computer generated characters. Optionally, players could order as many characters as they desired and play them as a group.
The gamemasters sent an adventure scenario to the players describing events and problems, and the player wrote a text description for how his character(s) would proceed. The game went back and forth in this vein, with the gamemaster responding to the player's plans and actions, and over the course of time a complete adventure unfolded.
Each exchange between the player and the gamemaster was a "move".
The designer of Silverdawn and his staff went on to publish several fantasy adventure modules with generic utility for any heroic fantasy RPG system, and a "World of Silverdawn" -- which included a 22" x 17" full color map of the gaming world along with a booklet describing dozens of locations and points of interest.