This came up last night, and the DM and I wanted to ask around to see if anyone could clarify this for us.
I'm playing a Pact of the Chain warlock (with the voice of the chain master invocation, if that matters), with an imp familiar. The question we have is this:
If my familiar is out of my sight and I'm not actively thinking about him, would I know he has been attacked? In the case that came up last night, I had sent him down to scout out some building for us, and he was flying back up to us (we were riding around on a magic carpet). The DM did some rolls and started asking about his armor class, with the intention of some npc (that I was also not aware of) hitting him with a fireball. If it had hit, my little imp buddy would have just died, without a chance to contact me and let me know he was under attack. So the question is, would I know about it instantly, or would I only know once I turned my attention to him and tried to issue a command?
My thinking was that I've always considered my familiar sort of a "third arm." Almost part of my character. But that's just head canon, that doesn't seem to be represented in the books. If that is the case, then I think I would know immediately. But if not, then I don't think I would.
We went over the spells and invocations and didn't really see anything. RAW, it doesn't seem to be a concept that's addressed at all in the books. So there may not actually be an answer to this, maybe it's just something we have to figure out for our game.
But if someone can answer this for me, it would be very much appreciated.