Free play refers to a specific type of promotion that is offered by some casinos, in which players are given a certain amount of money to use on certain games, usually slot machines. This money is not real money, but rather a form of "play money" that can be used to play the games but cannot be cashed out or withdrawn.

All in all, there are free slots that pay real money, but you will have to be playing at real money online casinos as opposed to social casinos on slot apps, or playing titles in demo mode.