Eh. They've defined rules that say you can't count cards. If you do so, you aren't playing by the rules, therefore you aren't allowed to play. It's slightly

Eh. They've defined rules that say you can't count cards. If you do so, you aren't playing by the rules, therefore you aren't allowed to play. It's slightly odd to set rules that define what you can and can't do within your own mind, but it's not out of bounds, just hard to correctly enforce. Lucky for casinos, they don't care about correctly enforcing, they just care about making money. They're happy to let you count cards badly and lose money, and they're happy to kick out people winning a lot, regardless of whether they are actually breaking any rules. It's sort of like cheating at playing Marco Polo. Sure, you're capable of opening your eyes when people can't see, but doing so is cheating, and calling out people you suspect of cheating but can't prove can be somewhat common.