Lavinia, Azorius Renegade {W}{U}
Legendary Creature — Human Soldier
Each opponent can't cast noncreature spells with mana value greater than the number of lands that player controls.
Whenever an opponent casts a spell, if no mana was spent to cast it, counter that spell.
click a line to search just that ability, click more to combine them
Cards that do something similar expected a card that isn't here?
Reports become test cases the matcher is graded against before an update ships. Delvefall isn't a chatbot guessing, it compares the printed rules text of every card with plain math, and examples like yours decide which differences should count.
Boromir, Warden of the Tower 100%
$5.62#837
"Whenever an opponent casts a spell, if no mana was spent to cast it, counter that spell."
Vexing Bauble 88%
$2.26#1316
"Whenever a player casts a spell, if no mana was spent to cast it, counter that spell."
Void Mirror 87%
$0.32#15339
"Whenever a player casts a spell, if no colored mana was spent to cast it, counter that spell."
Ice Cave 85%
$0.80#20895
"Whenever a player casts a spell, any other player may pay that spell's mana cost. If a player does, counter the spell."
Chancellor of the Annex 85%
$2.99#10150
"Whenever an opponent casts a spell, counter it unless that player pays {1}."
Bazaar of Wonders 85%
$2.78#28053
"Whenever a player casts a spell, counter it if a card with the same name is in a graveyard or a nontoken permanent with the same name is on the battlefield."
Counterbalance 84%
$5.98#3227
"Whenever an opponent casts a spell, you may reveal the top card of your library. If you do, counter that spell if it has the same mana value as the revealed card."
Cephalid Shrine 83%
$0.29#29975
"Whenever a player casts a spell, counter that spell unless that player pays {X}, where X is the number of cards in all graveyards with the same name as the spell."