[Senseisensor]

Is it possible to hack online casinos

[Mr. Monkey]

It's a very broad question.

What do you aim to achieve?
1. Getting user credentials?
2. Getting more in-game currency so you can withdraw cash?
3. Getting the next number on the roulette table?

Any of those achievements above would prove to be very difficult and would require weeks or months of research and figuring out how the site works (Not mentioning the years of experience in website pentesting).

Let me tell you one thing that would throw you in the right direction (IMO):
The most vulnerable link in the online casino's supply chain is not the online casino itself, but the players.
As a rule of thumb, the human component is the best part to take advantage of.