Here's our "rule"..........
"Rules" are a tinfoil shelter that offer the weak and thoughtless a false sense of security. Until the first good wind comes along.
We want nothing to do with "rules" !
Instead what we want & need are love, kindness, compassion & thoughtfulness (awareness).
If you can surround yourself with that and ACT in that manner a need for false shelters goes away.
I'd be careful of "rules". As we all know & say - rules are meant to be broken. And usually are because we can't have the foresight to see every possible combination of circumstances that life may throw at us.
But we CAN always choose our actions with the best intent for all concerned.