>>519787122
>They also allegedly used special contact lenses or eyeglasses capable of reading pre-marked cards, and an X-ray table that could read cards even when they were placed face-down, according to the charging documents
It just needs to be something simple to identify marked cards using some sort of sensor.
Then the players are fed that information and how to proceed betting to get the victim to raise the pot despite zero chance of winning.
If you trust Vegas they have inspections to prove no one is being cheated other than house advantage.
A random underground poker table, all bets are off.