The Buddha's teachings assist us in overcoming greed and attachments to things such as ego and extreme viewpoints. Addictions are to be avoided of any kind. While it is certainly possible to become addicted to gambling, it can be just as easy to become addicted to many other things, including compulsive behaviors and viewpoints.
In the Buddha's teachings, there is no "sin." Negative or unwholesome things might happen because of attachment (or greed), aversion (or hatred), and delusion (or ignorance). Participating in entertainment activities is not forbidden and can be done in moderation, especially without extreme attachment and greed. Studies show that the vast majority of all tourists and locals who do gamble, do so with a strict budget.
It is specifically mentioned in the discourses of Buddha, Digha Nikaya, Sigalaka Sutta, number 31, that lay people should not waste their money and one way of wasting money is described as addiction to gambling. The discourse does not prohibit gambling or entertainment, just the addiction to it.
There are some who believe that it is inappropriate to live in Las Vegas or especially to work in casino establishments. Such a viewpoint fails to understand the intentions of our actions. The Buddha only was opposed to livelihoods that directly harmed others with violence, including trading in weapons, poisons, and animal flesh. A casino black jack dealer has no intention of creating a gambling addict anymore than a TV cable installer wants to create a TV watching addict. Working at a casino is not a wrong livelihood.
The viewpoint against living or working in Vegas fails to understand the interconnectedness of all life, people, and economies. A tourist may come to Las Vegas, win some money, take it back to his home in Cleveland and buy some lunch at a cafe in Cleveland. The cafe owner is then receiving gambling money (indirectly) which he then uses to pay his employees. One of the employees uses the wages to buy some products at a store in Cleveland, which pays another owner which pays another employee, who then might use the wages to make a trip to Las Vegas. The cycle goes round and round, it is all inter-connected, just like Indra's Net and the circle of life. To say that you can not live or work in Las Vegas so that you do not touch gambling money is foolish, it is all connected no matter where you live.