Using Magic: the Gathering and its rules as base, efofecks and his friends made some pretty cool decks based on the StarCraft universe. Their fan-made project consists of three 60-card decks (Terran, Zerg and Protoss, obviously) and it's meant to be played 1v1 with two different decks.
The set has been heavily playtested so that any two different decks are, on average, balanced against each other. We have not tried a 3-player free-for-all game nor a mirror match. Decks are two colours for stronger identities and more fluid mana bases. We stick to MTG's colour pie, except for rare cases where we felt flavour bending was justified (and even then we don't tweak it much). This set was balanced to be print-and-play, not for cube or draft. Rarities don't mean anything except to signify card complexity (and sometimes power).
Each deck's design resembles the theme of that particular faction in StarCraft. Terran cards have a strong transformation mechanic, Zerg's all about sacrificing their own creatures, while Protoss has strong early game defences and even stronger finishers.
Here are a few examples below, and you can check out the whole thing over here.