Making money online playing games is possible and also so simple that even children can do. But first of all you must register on one or more sites that pay you to play games. You can register on one of these sites:
Paid GamePlayer offers reward points for playing free games which you can later redeem for various prizes. There are also tournaments where you are required to pay a fee in order to participate, usualy less than a dollar, but if you win in the tournament you can walk out with significant amount of money.
Exodus 3000 is an multiplayer online role playing game. By playing Exodus 3000 an completing various missions player earns virtual currency called mars money. Later you can exchange this virtual currency for real money.
Tournament games is another site where for a small fee you can enter tournament and walk out with substantial amount of money when you win.
Swagbucks is another reward site which has play games for prizes option. Swagbucks has many casual games to play such a s word games arcade games etc. When you accumulate enough points or as they are called swagbucks you can redeem the for Amazon gift card or cash through Paypal.
Game show network is another site that rewards you for playing games. When you play games you are rewarded points or as they are called on gsn.com oodles. Later you can redeem oodles for gift cards to Amazon, Walmart, Exxon Mobil and other stores.
Another way to make real money online is by selling virtual goods and virtual currency to other players. This way you redeem your points directly on the site but you find other players who are wiling to pay real money for in game money and items. There are also many sites where you can sell your virtual items and virtual gold for real money online. There are many MMORPG (Massive Multiplayer Online Role Playing Games) you can play and all the virtual money and in-game goods you acquire later sell for real money. Most popular MMORPG today probably is World of Warcraft. If you search online you will find many websites where you can sell virtual stuff and virtual money and earn some real money.