If by playing social slot games for real money you mean real cash prizes, then it's a matter of playing the games for free and winning a special currency used for prize redemptions, often called Sweeps Coins. You can usually collect Sweeps Coins and later redeem them for real money prizes. Just remember that playing social slot games are always free, and as long as you are mindful of your balance and use your chips responsibly, you shouldn't ever have to play social casino games with real money – the free play can go on for as long as you like, and purchasing Gold Coins for free standard gameplay is just an option!