Rogue Assassinate question

So i'm trying to build a rogue for the campaign next week, and had a question on the Assassinate ability for rogue. The description is that the enemy must not be aware of your presence.  Does that mean that if he has seen me, it rules out the ability to use the assassinate ability, or can a successful hide check cancel that out? because that honestly changes the effect of the ability, if it is only able to be used on a suprise round before they notice us, then it only gets used once a battle. if instead i can use it as a sneak attack sort of modifier then it can be a great asset.
thanks for your time
The rules are unclear on what that means. I've allowed an Assassination anytime the Rogue is hidden.
So i'm trying to build a rogue for the campaign next week, and had a question on the Assassinate ability for rogue. The description is that the enemy must not be aware of your presence.  Does that mean that if he has seen me, it rules out the ability to use the assassinate ability, or can a successful hide check cancel that out?

What it means is that it's 100% up to the DM to figure out what 'aware of your presence' means. The best thing to do is ask the DM to rule on it before hand so you don't end up with a nasty surprise during combat.

If a monster uses invisibility or hides the players dont ignore the existance of it, they take measures to search for it... thus being aware of its presence. I would rule the same applies the other way around as well so unless other circumstances apply I would not rule a simple hide for advantafe enough.

 Look at sneak attack Vs assasinate though. They have to be equal choices the difference at 6d6 mdd is:
 Sneak attack adds an average of 21 dam (6d6*3.5) (this increases drasticly on a crit)
  Assasinate adds an average of 18.5 dam (36-21+half shortsword dam) and target has to save or take 47+x (5 dex+6 shortsword+ 36mdd+ x for other buffs and magic weapon) extra damage. This is only improved slightly by crit.

 So with hide being the go to way of getting advantage there is no merrit to sneak attack if you can just hide for assasination.
I take it as meaning 'aware that you are there and that you are hostile'.


Once you have revealed yourself in the combat - even if you hide - he is aware of your presence.

But if you remain hidden while the fight starts - he is not aware of your presence.

If you can make a convincing bluff that you left (and it better be good) - you might be able to convince him that you are gone.  But it would take a couple rounds most likely so isn't worth it.

And if he knows you are there - but has no reason to think you mean him harm (DM interpretation) I might give it to you.

Carl
 One thing to keep in mind is also that a combat generally dont last for more than 3 rounds, so even with sneak attack it can be a task to get more than 1 in per combat.
Assassinate is far too powerful to allow players to use it multiple times with a simple hide check
Tho limiting it to surprise only is far too limited

I would say as long as the enemy hasnt seen the rogue (has been hidden since the start of the fight), he can use assassinate

If they have seen/heard him however, they are aware of his presence and fight more cautiously even if they cant see him (or fight more cautiously especially because they cant see him, but they know he is there)

Remember that Assassinate is a guaranteed crit, with a good chance of being a double crit
I don't know if anyone here has seen Ryan Gosling's movie Drive but it has a character (Bernie Rose played by Albert Brooks who is not his normal comedic character). 

When Bernie is killing (or attempting to kill in the case of Driver), he normally takes his targets completely by suprise, even in the case of Shannon, who he spends an entire scene talking to before slicing open his forearm with a straight razor.

Basically, what I'm driving at here is I'd like it to be an ability where the target is not aware you are a threat (either you are completely hidden and attack or you initiate combat in a non-combat situation such as negotiations).

I feel like I'm not completely explaining what I mean here so did I get the idea across?
I don't know if anyone here has seen Ryan Gosling's movie Drive but it has a character (Bernie Rose played by Albert Brooks who is not his normal comedic character). 

When Bernie is killing (or attempting to kill in the case of Driver), he normally takes his targets completely by suprise, even in the case of Shannon, who he spends an entire scene talking to before slicing open his forearm with a straight razor.

Basically, what I'm driving at here is I'd like it to be an ability where the target is not aware you are a threat (either you are completely hidden and attack or you initiate combat in a non-combat situation such as negotiations).

I feel like I'm not completely explaining what I mean here so did I get the idea across?




Yea, not aware you are a threat is fine, but they would have to be not aware you are a threat and have their guard down

Monsters and Thieves probably would have their guard up against you, but if you want to randomly assassinate the Village Inn keeper who is servering your drinks, then sure that will definitely catch him by surprise