Basically you need to find the official thread for the website on Bitcointalk and do your research. You can even use google for this. For Bitcasino here is the offical thread,

https://bitcointalk.org/index.php?topic=395617.0

And if you look at the owners user info,

https://bitcointalk.org/index.php?action=trust;u=207035

He doesn't have the best trust rating, And there is a good reply by Stunna which explains what is going on,
https://bitcointalk.org/index.php?topic=395617.msg21849237#msg21849237

Basically with all the available dice sites out there, just gamble somewhere else.