I am very confuse about what they call the gambling a game >.< its about spending money on nothing then why is it called a game? why don't call it money investment? kindly explain please? Thank you 
people call it a game because it is a game and spending money on it doesn't change it. the same way you go to an amusement park and spend money on the games. but the difference here in gambling is that you have a chance of winning some of that money back and even make a profit.
also it can not be an investment because it is risky and you can't manage it in a way that you always win.