Duplicator

Duplicator is a shared event (appearing in Acts 1-3) that adds a duplicate copy of one card of your choice to your deck. You select any card currently in your deck and receive an identical copy (same upgrade status). There is no gold or HP cost for this event.

Duplicator is highly valuable when you have a powerful card that benefits from having more copies, such as a key Exhaust-synergy card, a strong 0-cost card, or an important Power. Duplicating a core combo piece increases consistency significantly. However, duplicating weak cards or filler cards wastes the event entirely. The best use cases are duplicating upgraded Rare cards or essential 0-cost cards like Shivs or Anger. Duplicating Curses is possible but strongly inadvisable.