Is it wrong to gamble?
Absolutely not. Gambling in and of itself has no inherent wrongness. For some reason locked deep within the reptilian brain, we get a kind of pleasure from making an arbitrary choice and then seeing if a random (supposedly) system agrees with this choice. It's a little thrill even if we lose because there is the power we feel about putting something of value in the hands of fate. The thrill when we win is a more destructive kind of reward if it is seen as a
validation of our choice rather than as a stroke of luck. But gambling itself is a form of entertainment, and should be seen as such.
For myself, I often go to Vegas fully expecting to lose a certain amount of money. I see this as part of the entertainment of going there. I know I'm going to drop $40 or $50, just like I would if I were in San Francisco, buying a ticket to tour Alcatraz. It's an entertainment expense.
Is there a point in which it becomes wrong to gamble?
"Wrong" is an ill-defined term in my definition. People can certainly take gambling to extremes when they try to gamble to win. Gambling to win is inadvisable, irrational, and irresponsible. But
wrong? The part that may make it wrong has little to do with the gambling itself. If you drop $10,000 in one afternoon gambling, how is that different from spending $10,000 on any other fleeting thrill?
Are there any scriptural prohibitions against gambling?
On the contrary,
Ecclesiastes 9:11
"...the race is not to the swift, and the battle is not to the warriors, and neither is the bread to the wise, nor wealth to the discerning, nor favor to men of ability; for time and chance overtake them all."
This would seem to indicate that gambling is not only OK, but that it is the only thing you can believe in.