I bet that majority don't check on the T&C upon signing up, it's a lot of words to read and majority for sure are taking a shortcut and skip that part.

But at least after the registration, everyone has to look and see to it that they know the rules to know what are the do's and don'ts of the casino where they're playing at for example, in duelbits.
Yeah, Usually was checked after the registration since user excited to play that's why they are creating accounts. T&C requires few hours to read and comprehend so this things usually set aside for players to immediately start there game. In my case since I know the basic of T&C and I know already the typical do's and don't, I usually just scan it during the registration and proceed to gambling session just in case there's a special rules that will lock my funds in case I didn't follow it.
And because of the long words and too many characters, everyone will just hit the "I agree" and sign up button. It is what it is but when it comes to something that has been missed.
We can just go back there and read which part you're looking specifically if you think that there's a need to review or an exact rule that you need to know.
We must recognize that this is not entirely the fault of people, almost any website and piece of software that you use has their own terms of service so it is not really surprising that people do not read them.
However I have the policy of always reading the terms of service of any website in which I deposit money, that way I am sure that my account will not be closed due to my own fault, however if we are honest many casinos have similar policies, so once you have read the terms of several of them the time it will take for us to understand those terms will drop considerably.