Rule of Law

The cleanest possible answer to combo and storm, and one of the most blunt statements white has ever made about how much a turn should be allowed to do. The restriction is symmetrical on paper, but the asymmetry in practice is the whole point: a deck built to chain rituals, cantrips, and a kill spell into a single explosive turn dies under it, while a fair deck that was only ever going to cast one or two spells a turn barely notices. It hoses the act of casting rather than any particular card, so it slips under counter-magic countermeasures and graveyard hate alike; the only honest answers are to remove the enchantment or to find a way to win without casting at all. That bluntness is also its cost. It does not distinguish friend from foe, which is why it tends to live in decks that have already decided they want a grinding, one-spell-per-turn game and are happy to drag everyone there with them. Related designs explore the idea: Eidolon of Rhetoric stapled the lock to a body, Ethersworn Canonist narrowed it to nonartifact spells so artifact decks could play around it, Arcane Laboratory rendered it in blue. None of them is meaner than the original flat declaration that you get one spell, and that is all.