Part V: Regional & Cultural · Casino Slang & Historical Terms

6.16 Tell

Slang — Poker/Behavioral

A “tell” is an involuntary behavioral cue that reveals information about a player’s hand or intentions. In poker, tells can include changes in breathing patterns, hand movements, eye contact, betting speed, or verbal patterns. Casino surveillance and security personnel are trained to recognize tells that may indicate cheating, card marking, or collusion. Professional players study tells to gain advantage, while skilled players actively work to eliminate their own tells.

In practice

The concept of tells was popularized by poker literature and media (notably the movie “Rounders”). In modern casino surveillance, technology-assisted behavioral analysis supplements traditional tell-reading techniques.

One entry from the Casino Industry Glossary — 1,157 terms written for surveillance, compliance and operations professionals rather than for players. Definitions describe industry usage; where a term carries a regulatory meaning, verify against the instrument that governs your jurisdiction.