Whether as a player or as a GM, I believe that trust is the most fundamentally important thing one can bring to the table -- trust is what transforms good moments into incredible moments, what leaves doubt and mediocrity behind.
No one is perfect; people are going to make mistakes. They could be in decisions made in playing a character, or in adjudicating the rules, or perhaps in one's recollection of past events. Any number of things can be possible.
But to have experiences that truly surpass all expectation, to reach heights many do not even dare to dream of in roleplay, to experience emotion through one's character wide in breadth and deep in strength...there must be trust. The GM must trust the players to be true to their characters. The players must trust the GM to always judge in good faith.
And communication is the cornerstone on which this trust will be built.
I believe every experience at the table is a venture into cooperative storytelling, and I wish to discover the greatest stories with those who sit beside me.