The Stars Our Decimation is the name for a series of interrelated science fiction wargames built around the actions mechanic. TSOD games all feature hand-built rules, hex grid regulated movement, a unique actions system, and versatile unit design rules.
Voidstriker is one of the games in the series. It is a fleet-oriented game of starship combat. Ships and fighters battle in deep space and in the gravity wells of important worlds. The rules feature unique, playable vector movement with gravity effects around planets, versatile ship design rules, quick and detailed combat resolution, and easy adaptation to use of miniatures or starship models.
Ground Zero is another game in the series. It is a tactical ground combat game, best suited to running company-level combats. Rules are based strongly on Voidstriker, so if you know one, you'll have a pretty good handle on the other.