calculated roll
 

Получилось так.
$serverSeed=("1");
$clientSeed=("1");
$nonce=("1");
$seed= $serverSeed.','.$clientSeed.','.$nonce;
$seed=hash("sha512",$seed);
$offset=0;
do{
$number= substr($seed,$offset,5+5);
$number=hexdec($number);
$offset+=5;
}
while($number < 999999);
$luckyNumber = ($number % 10000) / 100;

echo $luckyNumber;