It is extremely suspicious how primedice STILL generates the client secret on the server and gives it to the player - it is a SECRET! The server cannot generate it.
PrimeDice CAN be made provably fair if the user changes it. However, PrimeDice is NOT provably fair when you start playing it.
Stunna, no offense but you have been saying the "new site 2 weeks" for a long time now like BFL.
It seriously takes ONE LINE:
var clientSeed = Math.random();
Sure, it's not cryptographically fair, but it is enough for a client seed.