free-moderation: the game itself costs money, but you can then play it for free.
commercial: the game costs money and you pay to play it, too.
open-ended: the game can run forever.
closed-ended: the game ends after a given number of turns, or when certain conditions happen.
snail: the game may be played by postal mail ("snail mail").
email: the game may be played by email.
www: the game may be played over the world-wide web.
fax: the game may be played by fax.
gui: the game has a graphical user interface available
computer: the game is 100% computer-moderated.
human: the game is 100% human-moderated.
mixed: the game is a mix of human and computer moderation.
rpg: the game is a role-playing game
wargame: the game is a wargame.
abstract: the game is abstract.
economic: the game has a large dose of econmics
sports: the game is a sports simulation.
modern: the game is set in the modern era.
space: the game is set in the future.
historical: the game is set in the past.
fantasy: the game is set in a fantasy world.
Greg Lindahl