Setting rules is necessary in some cases. And it’s also exhausting for both parts.
The one who sets the rule needs to first come up with the rule, then communicate it, then enforce it, punish non compliance and adapt the rule so that it gets to cover new cases and new behaviour.
The one who is subjected to the rule needs to understand it, absorb it, find ways to work within the boundaries set by it, and perhaps at some point fight to have it changed.
There are few things that create a greater divide than rules.
If you truly have to set one, be sure it comes from a place of recognized expertise and authority, it is well communicated and it is open-ended.
And despite the best efforts, be prepared to have the bond of trust broken.