Don't do it. Just don't! If you do... prepare to lose.
Gambling in EVE Online is just like gambling in real-life. It is fun, addicting, but ultimately it can end with you feeling cheated and miserable.
I never thought I would get into gambling in EVE. In this game you always are aware of scams and you keep a sharp eye out for them. Obviously, a non-official gambling website raises the scam-detectors.
So how does gambling in EVE work? Well, there is no official gambling services in the game (unless you count investing in the market as gambling, it is, and the many other risky activities in EVE). This is actually something I would love to see. I had great hopes that the "Walking in Stations" feature would include some form of in-game casino. Well, Walking in Stations didn't happen and neither did in-game casino's, but there is an alternative created by the playerbase. This alternative is the EVE Online gambling website. It works by keeping track of your character and it's balance on the website. For example, to gamble on Evealopalous you register your character and then send "x" amount of ISK to the "Evealopalous" corporation. This ISK will appear under your characters balance on the website and you can then gamble with it. Almost all EVE gambling websites work this way.
So, I've always wanted to gamble in EVE and without an official outlet I decided to try one of these website.
The first I tried was Evealopalous. Evealopalous features many games, but the most popular are the raffles and the "Grid". Raffles are just like they sound, you pay 10k ISK per raffle ticket and try to win valuable prizes. I got really burnt on these, I would buy anywhere from 30% of the raffle tickets to 80% of them. I never won.
I did however win on "The Grid". The Grid is kind of like minesweeper for ISK. You pay 2m per click and you have the potential to win clicks on other more expensive Grids or ISK prizes. This was where I won big. I won a "Grid piece" for 2m which lets me get a free click on the next higher tier of Grid (10m per click). Luckily, I won a click onto the next tier of grid with THAT free click.... finally, I won a prize, and it turned out to be 220m ISK! I was really happy about this, as it made up for much of what I lost with those damn raffles.
The other gambling website I tried was evetools.org. Evetools features scratchers and a slotmachine.
The slots where fun but unfortunately didn't pay out often enough, it was pretty easy to lose 80m and so I did!