Well. I hope that you learnt your lesson and will not participate in any kind of scammy looking game anymore. Most ponzi schemes is very bad in 2016.
Apart from that, I would have to say that I have gambled away some important funds that I have needed badly. However, I have learned my lesson now, and I definitely won't do it again.
You should have checked their profile and trusts (if at Bitcointalk) before deciding to lend them Bitcoin.
Good that you have learnt your lesson and will not gamble away any of your important Bitcoin again. And ... How about not gambling at all?
That is really a big mistake. 0.15 BTC is a lot today. Make sure you remember your passphrase next time.
I wish that I hold that for a week more.
I did this type of mistake too. I bought a lot of domains using Bitcoin at Namecheap when the price for a Bitcoin was 200 USD. Today, the price of Bitcoin is 400 USD. I could have bought 2x the amount of domains if I waited six months. .