Coindice - the script that Paradice is built upon - generates the number fairly in the sense that it's randomly chosen and not biased. It's provably fair at the hash level - the player's roll is the same as the roll that the site provides the hash of - but it's not provably fair at the RNG level. The admin could theoretically edit the code so that it generates biased results and players wouldn't know or be able to do anything about it (due to the lack of a client seed). However, it's unlikely that Paradice (or any other site) would do anything like that - such a system implemented without great care could make a site more vulnerable to potential exploits - and I'm pretty sure there's no scam going on here, at least with the rolls. MafiaCoin's 'proof' post makes no sense - at best he just has no idea how it works, at worst he's just trying to cause trouble.
However, while it's unlikely that the site is cheating, personally I'd advise steering clear of paradice unless they implement a true provably fair system with a client seed option and rework their rules. A 'one account per user' rule on a Coindice-based site - where users are likely to accidentally create multiple accounts due to the automatic generation of them - is suspicious and could be used as an excuse to withhold legitimate withdrawals, and the same goes for a horribly vague rule like 'don't faucet farm' rather than having specific limitations on the use of the faucet.
Yes I agree. Its a strange way of making the game provably fair because there is no "client seed" which can change the hashed result but it still means the game is fair and you can verify your hashed seed AFTER you roll and find out if you were scammed.
There are many sites that have a client seed which is generated by the casino, and most people never alter this seed. Which means that technically the casino can alter it in a way and hope you don't change your betting style so you end up losing.
Most people don't understand that usually the casino knows if your rolls will win or not before they are taken place.
Maybe there is a way how some casinos cheat this way or not. I mean its possible that the casino can learn that you are "Betting 50/50 and Martingale on losses" they can just hash some seeds ahead of time and choose one where they hope you will have sequential losses after a certain amount of bets. I mean its possible and even if you verified the seed, it would show that they were true.
Only way to protect yourself from this would be to manually change the seed after each and every bet.
