To do this trick you need to have some money to start.
First off, there are 3 cards right? One of the cards is the queen and the probability of picking the queen is a 33.33% chance out of 100%.
There are 2 things you can do in this game to make the probability the max of 66.66% chance of winning.
That means you will win 2/3 of the time. 66.66%
But, if you bet multiple times over and over such as $100 the first time, then if you lose, then bet $200, then if you lose again bet $400, the chances of losing are ZERO. (Provided you started with $10,000 plus and you are betting in denominations of $100 at the start, $200 if lost, then $400 if lost, and $100 if you win.)
So, what you need is to go to the gambling den here.
Once there, like I said you need to refresh the page until the Queen is in the middle.
Then after every bet make sure you always pick the far most left card. Not the middle or the right card. Always pick the left card.
Now if you did this, your chances will be improved to 66.66%. Try not to tell your friends how rich you got though =)