You know how you can guard exits?
I think it'd be interesting to be able to do the same thing to people.
Basically, if you walk into a room with a sleeper, you can kill them/grab them/anything them instantly, whether someone who wants to stop you is there or not. I thought it'd be interesting if there was a way, similar to guard, to 'get in the way', so to speak. Push them away, whatever.....like an opposed skill/stat test between protector and assailant.
Also, it'd be interesting to do this to people who are -awake-, except that, you would basically only be able to try and keep someone else from grabbing them. And, in combat, it'd be as though the other person were using you as a human shield (except, attacking would still be possible). Some hits would get through to the intended victim, others would hit you instead - basically, getting in the line of fire.
That way, protecting someone would actually be possible in a more direct manner.