This is precisely the case of Ameristar Casino in Black Hawk, Colorado, which reportedly faces a lawsuit by a player that allegedly counted cards. While casinos obviously do not like players that count cards and may enforce penalties such as permanent bans, based on the rules in effect for each gambling property, the activity itself isn’t classified as illegal in many states across the United States.īut while it may not be illegal, counting cards can cause lots of trouble for the gamblers that engage in such activities and the casinos that take action against them. Counting cards is an activity that casinos disagree with, but it is often difficult to spot, prove and even prevent in some cases.