I moderate a couple of light hearted communities pretty strictly. Name calling is not allowed, neither is arguing. Discussion is fine, but the second I see it become unpleasant, I shut it down.
That said, I’m the main contributor to the majority of my communities and I’ve dramatically decreased the amount of posts I make over the last couple of weeks. There’s a lot more criticism and negativity lately, and some of the abusive messages I receive after asking someone to abide by the rules are straight up unhinged. I have to moderate closely to keep it enjoyable and honestly, I don’t have the time or the inclination to deal with the nastiness at the moment. The crappy mod tools don’t help, and neither does me living in the UK when the majority of commenters are in the USA.
But anyway, check out the community rules and the stickied mod post in !dontyouknowwhoiam They might give you a starting point to create a nicer community.
The others I moderate - !confidently_incorrect!clevercomebacks!murderedbywords and !badrealestate - all have similar rules, with varying degrees of success. !badrealestate is definitely the “nicest” community I moderate - it’s pretty hard to get worked up over estate agent photos.