Gambling is always risky because in gambling we have only two choices either win or loose. So it is good to gamble with small investment,instead of loosing all money in gambling. Some time even with small amount of money we can make fortunes by winning jackpot who knows.
The first thing you should understand that gambling is not an investment, but it is just a game and needs to play when one is need of some entertainment. Most of the people use it wrongly to make quick bucks and end up losing a lot of money in it. But if one want to invest money in any casino bankrolls then small amounts also works, and over the time we can increase our investments.