(This post is about the popular Commander/EDH variant for Magic: the Gathering.)
Commander has two rules that prevent players from using cards that aren’t of their commander’s colour(s): a deckbuilding rule and an in-game rule.
- Cards in a deck may not have any colours in their identity which are not shared with the commander of the deck. (The identity of each card in the deck must be a subset of the General’s.)
- A deck may not generate mana outside its colours. If an effect would generate mana of an illegal colour, it generates colourless mana instead.
In this post, I would like to discuss the possibility of removing the first rule, and relying entirely on the second rule to keep decks colour-segregated. I will merely list all consequences I could think of, and let the reader come to their own conclusion.