I wondered about this a long time now. Every time I play games I get a form of satisfaction. This satisfaction is accomplished in a virtual world using real effort. Games work, by definition, using game mechanics.
Game mechanics are a construct of rules intended to produce an enjoyable game or gameplay.
Usually, most games are known to be just 'games'. Nobody takes it as something that has notable consequences afterwards. Some of the more serious games could be sports ( they involve your body and ). Virtual games are games that are based within a virtual framework. They 'work' only inside that framework. I am sure you are familiar to modern video games. They are remarkable in the experience and satisfaction they offer to the player. Video game industry is one of the fastest growing form of entertainment.
As I have seen in a TED talk
here, games can be used to motivate 'players' in real life by adding a virtual reward system that is contained in a game overlaid on top of reality. This system is currently under development and I am sure it will be very powerful as the smart devices ( e.g smartphones ) industry is getting bigger and bigger. The possibilities are very powerful. By associating any action with it's virtual counterpart situated inside the game, using a point-system that keeps track of your progress, you can empower an individual and motivate him. This can also be used, for example, in environmental issues, real social interactions, marketing, etc.
The thing about the game layer that is overlaid on top of the world is that every person knows it is not actually real. Not real in the sense that any action inside the game does not affect reality. Imagine a game that, somehow, convinced every player that everything that is happening in the game is real. How can you do something like that? If you base that game on a virtual device ( e.g. a computer ) people will realize it is not real because everything that is happening in the computer does not profoundly affect them ( e.g. a computer program cannot feed you ). You need a wider base. A base that can support the reality concept.
A base like the human mind. Everything inside our mind we consider it "real", but that is obviously uncertain, because every piece of data that enters our mind are coming from our native instruments, our eyes, ears, etc., and they cannot be 100% right ( see optical illusions ), thus they are uncertain. Reality, also, is a concept that lives purely in our minds.
If you could create a game that happened inside our mind, where our mind keeps the score, our mind knows or changes the rules, then you could get a satisfaction by achieving something inside that virtual world ( even though it doesn't usually influence reality ). That satisfaction could be even more amplified if that game has "real promises". If, in the game, you promise a real reward after achieving something inside it ( like in online poker ), you amplify the desire to play that game. If the promised reward is even greater than anything that is in reality, then the player will usually choose the game instead of reality. You can go in the other direction and impose a real penalty if you do not play the game, or you do not play it well, or you do not do a specific task, or if you break the rules of the game.
That would be a pretty captivating and powerful game. I wonder how could you even invent that game? Oh, I know! How about...
Religion! It is the best game you will ever play. Inside you mind, you will think that there is a God that watches you and changes every aspect of reality ( i.e. the virtual layer ), who imposed some rules that you have to follow ( game rules ), and if you don't respect them, after you die ( when it is "Game Over" ) you will either suffer an eternity a pain that cannot even be achieve in real life ( a negative punishment that is greater than any punishment possible -> infinity ). If you respect everything( play the game well ) you will go to heaven along with God and live for ever and ever in happiness so great that you cannot achieve it on earth ( positive reward that is greater than any reward possible -> infinity again ). The ancient holy texts contains all the game mechanics that fuel the game.
The best part is that you won't even know that you play a game -> game is confused with reality.
Now play the game! I heard it has the best graphics out there! It will be a blast!