Sludge Monster is an odd way to remove threats, but it does it incredibly well, and if you can then copy it as well, youll be laughing
If you are instructed to cast a spell with overload "without paying its mana cost," you can't choose to pay its overload cost instead
A pattern of cards has popped up in red cards that let you take a creature from your hand and put it on the battlefield, getting around casting costs and counterspells, though they generally have the trade-off of having to sacrifice that creature at the end of the turn
You can't bring your own fire extinguishers
Powerful cards like Fog, Burning Anger, and Spirit of the Labyrinth/Eidolon of Rhetoric offer unique effects
Leyline of Abundance Leyline of Abundance can have a big impact if youre running a lot of mana dorks, especially if you spike it into play with the leyline text