If an NPC in an enemy faction doesn’t immediately attack you, what do you do?

[StaceyPowers]

Sometimes in games, there will be a rare occasion where you’ll approach an enemy faction NPC, and they will not be aggressive. They may engage in dialogue, and you might have an option to kill or spare them. What do you usually do, and why?

Usually unless they give me a compelling reason to kill them, I leave them alone. I figure they’ve already shown themselves to be exceptional in some manner, and if they don’t get in my way, I don’t want to get in theirs.

[killamch89]

Nope - they're definitely dying. I don't want to risk them becoming even stronger and coming back as a threat in the near future.

[Heatman]

If you are an enemy and I have the opportunity to eliminate you, you're dying immediately, there is no room for doubt. 

[Justin11]

Since they aren't targeted enemies, killing them makes no sense. I am simply chasing after the main enemies to eliminate to satisfy my curiosity.