Text (SH+errata): 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. [Oracle 2009/07/08]
The cost reduction can be applied to extra costs such as Gloom. [D'Angelo 1998/02/27]
Will not add a 1 generic mana cost to abilities with no generic mana in their activation cost. [Barclay 1998/02/27]
It will never reduce any colored mana portion of an activation cost. [D'Angelo 1998/11/06]
