There are many combination of cards that provide an infinite amount of moves that take away from the game when a user chooses to utilize them in such a way. i.e. card - untaps when gains life. Paired with an enchantment - tap to create 1/1 creature . If they have 'when creature you own comes into the game you gain life' with the two above they have infinite tap/ create. It just makes everyone quit. This should not be allowed.