I wish to know if these games such as FPS which you can put for example in a room of 10 players everyone puts 5 dollars and the winner takes the whole 50 dollars, Are considered as gambling.
that's pure gambling. That's pretty much the same like when you put money and then the only winner who will be taking the whole of reward. that's different when you are competing like in the big competition. It's caused by the money being used as reward was coming from the creator of competition. I think that it can be seen from you were gambling your money to become a winner. Once you will be able to winning the match and then you will take opponent's money too. That means you are gambling and your skill was playing as a way to win the gambling.