The non-negotiables

I had a conversation with a friend of mine several weeks ago and he was talking about the different friends he has in his life. Friends that he grew up with, friends from school, friends that he is currently doing life with, to him they all were the same - friends. That struck me as strange because I see differences in my friendships. I see them falling into groups more like a target. I have those in my inner circle - those that know me really well and have open access to my life. These are the ones whose opinion I seek out, challenge me, encourage me, know the quirks I have, know me at my best and also at my worst. Then there is the next ring of friends who are good friends. We may have some things or interest in common. I can have an easy conversation with them but they probably don't know my deepest thoughts or concerns. Glad to hang out with them and have fun with them, but probably not at that level where I have developed a complete trust in them. Then there are my buddies. People I might know enough to chat with or spend some time with in a group setting. They know me at my surface. To me this is the level most people (especially guys) settle at. This is what they call friends. Not right or wrong, but I think it is settling for a lot less than what we were intended to have. My question (after that long introduction) is this - what 2 or 3 qualities would say are non-negotiable for you to have a deep friendship with someone? I think we all have that list whether we verbalize it or not or even think about it. Looking at those closest to you, what are the things you won't comprise on in your friendships? Their personalities may vary (my do anyways), but they have some definite things in common. Curious what makes other people tick.