let's explain this way, there is not any pure randomness in video games. Devs always manipulate randomness to balance the player's experience. In a very simple situation like this game, a senior game designer always monitors the dice value and didn't let it roll over all possible numbers. for example, if the player encounters 2 values 1 after 2 rollings, for the next round, the game designer removes values 1, 2, or even 3 from possible numbers to let the player receive a big number to balance his experience. it's a very disappointing experience that the player has tried so hard for winning the waves and every time we have given him a very little prize for this. so, we must handle this bad luck sequence and give him a promising prize and the best and simple solution for this is to manipulate possible numbers for dice rolling.