If you are a new player, this is a reasonable question to ask. So /roll is the way that we Role play on this server because not everyone is a Honor Role Player. To answer your question, it depends. Here are some scenarios:
*Josh attempts to punch Conor in the nose.
* Josh rolls 57
*Conor rolls 64
*Conor Dodges just in time for Josh's fist to miss his face.
Now let's say Conor has Josh on the ground, in pain, clutching his leg.
*Josh grabs Conor's throat with a forceful grip.
*Josh Rolls 89
*Conor Rolls 2
*Conor's face starts to turn red.
*Josh Tightens his grip on Conor's neck.
*Josh Rolls 92
*Conor Rolls 89
So if Josh keeps on choking him, he can eventually kill Conor if he wanted to. But if Conor has enough strength, he can kick josh off. So yes, you can be killed by /roll depending on the action that the player does.
Have a good Day!