Be careful with town adventures
Every day, I see questions about what to do after the PCs have killed some town guards or otherwise broken laws. Maybe it's the algorithm serving them up to me because I comment on them, but I think it deserves a post.
It's certainly possible to have adventures in a city or other civilized area. My current campaign takes place entirely within a city. But it needs to be handled with care.
Talk to your players about expectations and specific preferences. If your preference is that they don't ever kill guards, tell them that. If they're "free to do anything, but must accept the consequences" lay out a bit of what those consequences can be and how to have fun during them. And be prepared yourself to follow through on those consequences. Or, if you can't, but still want realism, give yourself some wiggle room.
That's basically the advice. Here's why I think it's necessary.
Players have egos and often make characters that are extensions of those egos. Town guards are usually created to indicate or impose restrictions on PCs, and so it might seem like PCs, especially good-coded ones, wouldn't fight them. But guards that are the least bit unhelpful, or who challenge the PCs, get in the way of that ego, and give an incentive for PCs to intimidate, slug, and eventually kill them.
For better or worse, D&D characters are designed with destructive capabilities in mind. The default assumption is that they'll be confronted with foes that any reasonable person wouldn't mind seeing killed. Setting aside how problematic that can be, subverting it for a town adventure, without setting clear boundaries on it, is asking for this kind of trouble.
Anyway, I suppose this won't really affect anything, and will probably spur some arguments, but it had to be said.