How does Trap / Undead Persistence work?
Trap Combat Only usable before range is determined on the first round of combat. Each round of combat has a press, only usable to continue combat. This continues until 3 rounds of combat pass with no cards played. After you play this card, every round has a press to continue. This press can be cancelled by another press played by you or the opposing minion, but otherwise combat continues to another round. The three rounds of combat with no cards played have to be consecutive. In the third round with no cards played, there is not a press, and Trap’s effects discontinue. Undead Persistence Inferior: Prevent this vampire from going into torpor. This vampire gets an optional press. When combat ends, or if 3 rounds of combat pass with no cards played, this vampire is sent into torpor. Unlike Trap, this card only provides one press. For any further rounds of combat to occur, presses must be played as normal. The Undeadly Persistent vampire is still wounded (see section 3.2); it just does not