Borderlands is a great fun game that I really enjoy, but is very violent. You shoot
aliens, animals and even human bandits. This probably worries parents most. What I think is, If your Child can handle violence it should be OK. Know their is blood and gore, and some disturbing images. I can say their is a reason for it to be M. Now If you know your child can hadle that think about swearing. Yes, their is a wide variety of swearing. Now if you have given it a thought, you should see the game first, right? So on youtube go to paulsoarsjr's channel and find his family friendly borderlands videos. Then if you approve the game should be OK. I would recommend it for a mature 13 year old. Good luck!