Does playing violent games affect you grades

No. Not that much. It just makes you want to play more and more each day.

Yes! The time away from the game will affect everything because you will be thinking about playing the game(s) instead of concentrating on what you should be doing. But most of all it really affects your basic spelling/reading skills. Please reread your question. ....affect you? grades? Just in case you still don't get it you're missing a letter