Part I: Card Game Cheating · CARD MARKING METHODS

Edge Marking

How it works

Edge marking involves making small marks on the edges of cards rather than the backs. These marks can be felt by the cheater’s fingers when riffling through the deck, or seen when cards are held at certain angles. Common techniques include small nicks, scratches, or color dots applied to one or more edges. Different positions and combinations of marks indicate different card values. This technique is often used in combination with other marking methods.

Where it appears

Poker, Blackjack, any game where the cheater handles the deck

On the record

Edge marking is one of the oldest techniques, used before printed backs became common. It is still effective today because edges are less frequently inspected than card backs.

Published as a detection reference for surveillance, compliance and gaming-operations professionals. Thresholds and tuning are set by the property. Nothing here is instruction — the method is described so it can be recognised.