River of Tears

Oracle Text

T: Add U to your mana pool. If you played a land this turn, add B to your mana pool instead.

Card Rulings

11/17/2017 The turn you play River of Tears, it will produce when tapped for mana.
11/17/2017 River of Tears produces only after you’ve played a land, not after you’ve put a land onto the battlefield (such as with Evolving Wilds).