Heartstone

Artifact, 3 (3)
Activated abilities of creatures cost {1} less to activate. This effect can't reduce the amount of mana an ability costs to activate to less than one mana.
"Finding a true heartstone is even harder than finding a true heart."—Hanna, Weatherlight navigator
Illus. John Matson

Gatherer Card Rulings [Nov 2009]

• 10/4/2004: The cost reduction can be applied to additional costs.
• 10/4/2004: It will not add a {1} to abilities with no generic mana in their activation cost.
• 10/4/2004: It will never reduce any colored mana portion of an activation cost.
• 7/15/2006: Can’t reduce Snow mana costs.

Format Legality	Legal in Vintage, Legacy Banned in Extended, Standard, MTGO Classic
Printings (2/7)	Premium Deck Series: Slivers (Uncommon) Stronghold (Uncommon)