Several casinos have their minimum withdrawal fees that they have set up and which all their clients must adhere to. Personally I know that the minimum withdrawal fee by casinos is mostly to offset or process transaction fee that could happen during withdrawal. But what I don't understand is how this works. If a casino says their minimum withdrawal fee is $10 and I have won $100 which I want to withdraw. I am able to withdraw the $100. so where did the money the casino use in processing the transaction fee come from?
You are definitely getting something very wrong here, first, there is nothing like "minimum withdrawal fee" on casinos, what casinos have is "minimum withdrawal limit" which is the minimum amount you can withdraw, the fees the casino is going to charge you to process your withdrawal is often stated separately, for example..
There is no way you win a $100, and withdraw exactly $100 out of the casino when they said you will charge $10 as withdrawal fee, if and when you are withdrawing the $100, the casino will deduct $10 which is the fee that covers the blockchain transaction confirmation as well.
And lets say that you a casino charges $1 for withdrawal, with a minimum withdrawal limit of $1, the casino excepts you to only request for withdrawal when you have and are withdrawing more than $1, for example, if you request a withdrawal of $2, $1 will be deducted and the remaining $1 sent to your provided wallet.
This is how it works and I hope this is easy to understand.
The OP should understood it by now, because most casinos are already showing their withdrawal fees upon withdrawal. If not, they will deduct it from the amount you are withdrawing. Very few casinos don't charge for withdrawal fees. Do remember, there is transaction fee in any blockchain. But for some, the fees are quite small, and that's when some casinos will shoulder that amount. But for btc, usdt, eth - in most casinos, they charge a certain amount upon withdrawing these currencies.
For example, in stake, they change the min withdrawal limit as well as withdrawal fees in btc, depending on the current fees on this network. However, it doesn't change everyday, it can be weeks depending on the market trend. You just need to look the fees and min withdrawal limit before withdrawal so you won't be surprise.