Can you make real money by playing games?

You need lot of people to be watching you to generate money, and no, is not ilegal

You can make money by participating in gaming competitions. Also, streaming is a good prospect but will take some time to establish yourself in the scene.

Making money over the phone is relatively difficult, but it is possible thanks to advertising

If you are Pewdiepie yes hahah or another big Youtuber with a great amount of viewers.

Yes, but whatever you do whether you go done a Youtube root, a Twitch root, a server root. Do it for fun let it start as a hobby because if you invest too much into it there's a lot to lose, only invest a lot and get into the business mentality after you find some success,