Common Courtesy{2}{U}{U}
Enchantment
Whenever a player casts a spell without asking your permission while casting it, counter that spell.
When a player asks you permission to cast a spell and you refuse, counter that spell and sacrifice Common Courtesy.
When a player asks you permission to cast a spell and you refuse, counter that spell and sacrifice Common Courtesy.
"You didn't say the Magic word."
Artist: Mike Raabe