Card

Deafening Silence

Mana cost {W}

Each player can't cast more than one noncreature spell each turn.

Part of 3 known combos, 3 of them two-card. 3 official rulings.

Bracket

B1 Exhibition — Not in the same deck as its two-card combo partners: Knowledge Pool, Possibility Storm, Eye of the Storm
B2 Core — Not in the same deck as its two-card combo partners: Knowledge Pool, Possibility Storm, Eye of the Storm
B3 Upgraded — Not in the same deck as its early two-card combo partners: Knowledge Pool, Possibility Storm, Eye of the Storm
B4 Optimized — allowed: No restriction beyond the banned list
B5 cEDH — allowed: No restriction beyond the banned list

Two-card combo with Knowledge Pool, Possibility Storm, Eye of the Storm (early with Knowledge Pool, Possibility Storm, Eye of the Storm)

Bracket: Lotus Vault analysis, with Commander Spellbook flags

3 known combos, 3 of them two-card.

Deafening Silence + Knowledge Pool
Produces: Lock, Exile all noncreature spells players cast from their hand, Players can only cast one noncreature spell per turn
View on Commander Spellbook
Deafening Silence + Possibility Storm
Produces: Exile all noncreature spells players cast from their hand, Players can only cast one noncreature spell per turn, Lock
View on Commander Spellbook
Deafening Silence + Eye of the Storm
Produces: Exile all instants and sorceries players cast from their hand, Players can only cast one noncreature spell per turn, Lock
View on Commander Spellbook

2019-10-04 · Wizards of the Coast
Deafening Silence will look at the entire turn to see if a player has cast a noncreature spell yet that turn, even if Deafening Silence wasn't on the battlefield when that spell was cast. Notably, you can't cast Deafening Silence and then cast another noncreature spell that turn.
2019-10-04 · Wizards of the Coast
Players may cast any number of creature spells plus one noncreature spell each turn.
2019-10-04 · Wizards of the Coast
If you cast a noncreature spell that was countered, you can't cast another noncreature spell that turn.

Rulings: Scryfall · Wizards of the Coast