Quad S Evolution is the second edition of the Quad S Spaceship Combat system. It is available in a pay-what-you-want format. The authors write:
Quad-S has been sold over 2000 copies in eight countries since it’s debut. Everybody from veteran gamers to new blood having its first taste of non-mass market gameplay is being introduced to Quad-S every week. With that kind of following, we had to come out with a second edition. Quad-S Evolution.
The basic premise that made Quad-S special has not changed. Quad-S is still a maneuver-based game that rewards good tactics. Every race is still diverse and plays by a different set of rules that is still compatible with the other races in gameplay. With honorable playing still a major for the spirit of the game, it is one of the main reasons Quad-S is still popular years later, is has generated a fan base of the “good” gamers.