From what I understand 999dice is not a scam
But by scam do you mean not fair or they dont pay out?
Both, they are not fair and do not pay to big winner. See the link which i gave on above.
I've played in 999Dice last week, Deposit 0.1BTC , withdrawed 0.12BTC after few hours of playing and i received my deposit in my web wallet. So i will not say that this site is scam.
So you want to say this is a legit site? To everyone who still think if this is not a scam site, Did you even once seing someone won a lot from this site more than 100 btc? Never, isn't it?