http://freebitco.in/ Why does the amount of Bitcoins that you can win, keep changing? The amount of bitcoins that you can win with FREE PLAY depends on the current bitcoin price and the biggest prize is fixed at US$200 and the other prizes in proportion to it. So, when the price of a bitcoin goes down, the reward amount calculated in bitcoins goes up and the other way round is also true. So, regardless of the current bitcoin price, you have a fair chance of winning US$200 in bitcoins on each roll.