Rotting Regisaur

Jul 12, 2019 · If you have no cards in hand when Rotting Regisaur’s triggered ability resolves, you simply don’t discard any cards. There’s no penalty for being unable to do so.

Jul 12, 2019 · Because the upkeep step is before the draw step, you discard for Rotting Regisaur’s triggered ability before you draw a card for your turn.