Rule of LawstaxBudget$0.44This is the closest functional equivalent, with the same static tax on spell casting for every player. It fills the same anti-combo and tempo-disruption role in white instead of blue.
Eidolon of RhetoricstaxBudget$0.44It imposes the same one-spell-per-turn restriction on all players. Being a creature makes it easier to interact with differently, but it serves the same locking function.
Deafening Silencestax$0.87A cheaper variant of the same spell-limiting effect, though it only restricts noncreature spells. It is a strong budget alternative for slowing combo decks.
Archon of Emeriastax$2.67It also limits each player to one spell per turn while adding an additional nonbasic land tempo tax. It broadly fills the same hatebear/stax role with extra upside.
Curse of ExhaustionstaxBudget$0.40This enchantment similarly restricts each enchanted player to one spell per turn. It is a more targeted version of the same anti-combo effect.
Sanctum Prelatestax$3.08While not identical, it can shut off a key portion of an opponent's deck and function as a lock piece in similar control shells. It is a more flexible creature-based prison tool.
Drannith Magistratestax$15.81It does not copy the text exactly, but it prevents opponents from casting many spells from non-hand zones, which overlaps heavily with anti-combo lock strategies. It is a strong protective prison piece.
Trinispherestax$20.15This is a classic combo-hate piece that makes multiple-spell turns much harder by increasing the mana burden of each spell. It is broader than Arcane Laboratory, but plays a similar lock role.