In different places (states, countries) there are a variety of rules, the goal of which is generally to let people have things like a fun Xmas raffle without opening up the opportunity to run "The Numbers Game" or similar.

To allow a raffle, dodges often enshrined in law include:

* Very low prize limits (e.g. max $100) but donated prizes don't count towards that limit. So your local charitable raffle has no problem getting a nice bottle of Scotch, dinner for two with wine at a nice place, family portrait, whatever local merchants want to donate, and it's all fine, so long as they don't buy it.

* Exemptions if you can only buy tickets in one place, or if you only sell them to members of your organisation that exists for some other purpose (e.g. a local church, employees at a factory)

* Exemptions if the profits of the gambling go to a recognised charitable organisation.

* Exemptions if there's no profit at all, all is spent on prizes that go to ticket buyers randomly, so the whole operation only moves money around randomly inside a group of participants.

In the UK there are special rules about raffles and lotteries on a small scale, and apparently they are only legal when for "a good cause" - http://www.gamblingcommission.gov.uk/for-the-public/Fundrais...

Raffles guarantee a winner. Picking a single person from a group of people have a very different probability profile than picking a number from a set of numbers that may not have associated lottery tickets.