I’m not sure a smear campaign, or talking badly about someone to others, is something only NPD people do, because I had an ex friend who I’m pretty sure did this to me. She had issues, but I don’t believe at all that she had any narcissistic tendencies. Honestly, the way that mutual friends treated me afterwards, I’m pretty sure she said things about me that were not true, too, because I never did anything to deserve the disrespect that I got afterwards. That is more reminiscent of a true smear campaign, when the person makes up things about the other. Idk, maybe I’ve just been surrounded by narcissists my entire life and don’t know it.