If you play a games for money than its gambling.In gambling i think it's all about luck.Going to risk money just try if you're luck or not.It's gambling.
I think same game if you play just for fun and no money involve then it's just a game.
Well for me game is a general term that has several types. Gambling is a kind of game where you put in wagers. So i don't think you can really differentiate as they dont belong to the same category.