When you are placing a wager you should know that you can not until you are getting paid.

If you do not want to insult the casino owner, you should be professional and to know that you can not ask to replace your deck of cards, that will be a total insult to the casino owner.

If you are sure that the deck of cards is the problem, just move to another table in the casino.

Do not use offensive language when you are inside the casino or when you are in an online casino room.

Never ask the dealer in the casino or the online casino's chat what is his hole card.

There is no dealer in the world that will risk his job in order to help a casino player to win. You can always ask the dealer for a tip, but not after he looks under his ace/face.

Do not blame the dealer or the Webmaster of the casino you play in for a bad hand (in a poker game for example), it could always be just bad luck, or – let's admit it, poor gambling skills.

Enjoy your gambling.