Metalcraft — : Add one mana of any color. Activate only if you control three or more artifacts.
Legal in
Modern, Legacy, Vintage, Commander, Brawl
Rulings (1)
If you control Mox Opal and one other artifact, then have a second Mox Opal enter the battlefield as your third artifact, you can't activate either one's mana ability before putting one into your graveyard due to the “legend rule.”
