How do things work around here.

[Clodfobble]

I think the trick is differentiating between the type of sarcasm you use with your friends, and the type of sarcasm you use with your enemies, and the fact that it's rarely a good idea to use sarcasm with strangers. Also, it's important to remember that not everyone here is friends with everyone else, so you may see two Dwellars being genuinely rude to each other, and if you don't know about whatever long-running baggage the two of them have going, you may assume that this is how people here treat their friends.

Really, it boils down to becoming familiar with each person here individually. Then you will know, when a person says something to you, how they meant it. If you don't know them, react to whatever they say the same way you would to a stranger on the street.