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.
You are probably not aware on why too many users calling 999dice is a scam, if you are aware you won't try to play at this site in the first place. Many accusation has been thrown to them with very sttong valid proof