Well anything you put on your phone is going to most likely provide a small amount of protection against scuffs, shattering screens, and dents. Some cases do better than others, some cases aren't meant for protection, just a certain feature.
The reality is though that unless you put your phone in a gigantic otterbox case where it seems like it's under an inch of armor on every side, it's possible to drop it and have something get messed up.
Sent from my HTC One M8