Magic: the Gathering is a trading card game, one of the most longstanding and successful on the market.
Given its length and number of cards, it has become one of the most complex games from a rules standpoint. By this nature, the designers have needed to forge an extremely robust rules system to accommodate all their rule interactions.
Relation to the -mgbmix- Project
For this reason and my familiarity with this rules system, I chose M:tG rule structure to be the basis of writing structure used with -mgbmix-.