Bitcoin gambling is not prosecuted right now so you won't have any problems playing anywhere. A lot of americans are betting online with bitcoins and no one cares.
The issue isn't about that no one cares, its about that its still not allowed(even if noone cares), and if they start caring then you can be in a trouble.
Yes, there are a lot of American users but I feel that the gambling websites should at least blacklist the American IPs(it will at least keep the sites safe and more trustable ) however people who gamble wont stop gambling this way.
If you live in a country where unlicensed gambling sites are prohibited you would know that the country ISP's automatically block the websites in question. If they pass a bill to render bitcoin sites unlicensed these will get blocked too. Till then enjoy. Everything else is just chit-chat.
But don't you think that as a responsible website the site needs to blacklist the users who are gambling from a country where gambling is illegal?
Luckybit does it, everyone should follow them.
Some website does indeed banned the IP from specific country, i.e Satoshibet, if you are a resident of US, you cant play in there, as for luckyb.it, It does not really a matter if they did bann specific IP from a country because player can play the game without opening the sites
Still the main point is that it is easy to bypass all of this IP issue, so I dont think this will be a problem if you are playing it safely by connecting with a VPN