We banned basic land destruction of unmodified lands (including mass land destruction that incidentally hits basics like Armageddon and Jokulhaups), some of the more oppressive stax pieces, mostly things that create locks where people can’t play the game, a handful of cEDH caliber cards, and certain types of infinite combos (2-card infinite combos where one card is your commander, for instance). One could argue that this creates an imbalanced environment by favoring strategies that take advantage of these rules, like ramp decks and lands strategies, and one would be correct - we’ve banned a lot of the normal ways to counter those strategies, but we maintain an overarching ‘Don’t be a dick’ rule that has so far covered it.
What were the ground rules?
We banned basic land destruction of unmodified lands (including mass land destruction that incidentally hits basics like Armageddon and Jokulhaups), some of the more oppressive stax pieces, mostly things that create locks where people can’t play the game, a handful of cEDH caliber cards, and certain types of infinite combos (2-card infinite combos where one card is your commander, for instance). One could argue that this creates an imbalanced environment by favoring strategies that take advantage of these rules, like ramp decks and lands strategies, and one would be correct - we’ve banned a lot of the normal ways to counter those strategies, but we maintain an overarching ‘Don’t be a dick’ rule that has so far covered it.