PS: Planeswalker's Mirth, Enchantment 2W {3}{W}: Target opponent reveals a card at random from their hand. You gain life equal to that card's converted ...

Planeswalker's Mirth

3W: Target opponent reveals a card at random from their hand. You gain life equal to that card's converted mana cost.

10/4/2004 If the opponent has no cards in hand, then no life is gained.