Counterfeit happens when shared cards make a strong hand weaker or tied.
Explanation. The term reflects how your hand is “falsely improved” only to end up duplicated—or worse. For instance, holding A‑Q on Q‑10‑5, then another Queen appears on turn; your top pair becomes a shared board pair. Omaha players also use it: hitting the nuts only to see it matched by the board. Counterfeiting reduces relative strength and often changes hand value mid-street.