This is a common form of online gambling. With proper sales in an https://rcin.org.pl/dlibra/login?refUrl=aHR0cHM6Ly93d3cuZHdmLWxhYnMuY29tL25ld3MvbWFya2V0LW1ha2luZy12cy1saXF1aWRpdHktcHJvdmlzaW9uaW5nLWluLWNyeXB0by13aGF0LWlzLXRoZS1kaWZmZXJlbmNl of a PRNG algorithm such as Mersenne twister, the games will be fair and unpredictable.