What are the three most important things a relationship needs to make it work?

Affection, caring (aka being nice) and common goals.. (It's hard to be with someone if you have major conflicts of interests)

Trust,commitment and communication

weed booze and sex

The two most, and really only, important things that will make a relationship work, are the two people in it working and wanting it to work.

Assuming love and attraction are already in place, I'd say kindness, communication, and trust.

Money and the ability to destroy the other person's self confidence. If those two don't work, try rope.

"Love, trust & respect" so I was told once..

Trust, intimacy, a honesty for me.

Respect,honesty,good humor

Oneness!

Compromise, admin skills and the benefit of the doubt.

actual friendship? trust? loyalty?

Trust, friendship and respect