“Social casinos” are free-to-play casino games that allow you to turn your play money into real prizes through one means or another.
These are mostly a United States phenomenon and arose because of the unique gambling and financial transaction laws in the country: basically, online casinos are illegal in most states, but “play money” at mobile phone / web browser games isn’t considered an actual item of value so it’s OK to gamble with that.
So you can never cash out play money to real money directly, but it is OK to turn it into real prizes through various semi-convoluted means. Scratch that, as of 2023 we have a new development called “sweepstakes casinos” that is making the bold attempt to let US gamers play for real money online via a series of convoluted steps. But non-sweepstakes casinos will generally have you play with fun money, which turns into some sort of loyalty points, which are then redeemed for prizes.
Defunct Social Casinos