It is a $10,000 for the casino and a guard more than likely will lose his job, if a customer with someone under 21 is not kept on the move.
This does not only apply to guards. The law applys to all casino employess from the GM to the porters.
NV takes underage people in casinos very seriously.
Its not hard to enforce when a kid is in a stroller. The problem is with the 18 to 20 crowd.
The Palms has wrist bands for people that are 21 but look 18. That way they don't get carded by every employee they pass.