Paul Farquhar
Legend
Well, you want the PCs to stay weak, and if they only get xp for killing monsters, and they can't kill the monsters, then they will stay 1st level forever...@Rechan Probably the most basic change you will need to make is to change how PCs get XP. 5E is set up to grant XP for killing monsters. So that’s what players are going to try and do.
If you want them to do something else, you need to incentivize that. All the other advice here may be useless if when it’s all said and done, the PCs are still only going to progress by killing things.
Start with that.