"I can't hear them scream, but at least I don't have to listen to them beg."
—Phage the Untouchable

Smother

Destroy target creature with mana value 3 or less. It can't be regenerated.

"Before I hire new recruits, I test how long they can hold their breath. You'd be surprised how often it comes up."
—Zahr Gada, Halimar expedition leader

Duel Decks: Zendikar vs. Eldrazi

Destroy target creature with converted mana cost 3 or less. It can't be regenerated.

Magic Online Promos

Worldwake

World Championship Decks 2003

If a creature is copying something else, its mana value is the mana value of whatever it's copying.

A token has a mana value of 0, unless it is copying something else.

A creature's mana value is determined solely by the mana symbols printed in its upper right corner (unless that creature is copying something else; see below). If its mana cost includes {X}, X is considered to be 0. If it has no mana symbols in its upper right corner (because it's an animated land, for example), its mana value is 0. Ignore any alternative costs or additional costs (such as kicker) paid when the creature was cast.