So what are the keys of conflict? I feel that it is a mixture of all the things above that make for good conflict.
Without fully dimensional characters there can be no conflict to follow. Without action to show the conflict it doesn't move the plot forward. So when you are developing a story, you are drawn to the possible conflict.
For example, my current WiP is an action adventure story and the conflict is many fold, however, the key conflict is internal to the main character. He knows what he has to do to protect the girl, but by doing so he will have to open up about his other side that she doesn't know. So the internal conflict pulls the plot forward.
What are some of you favorite devices for creating conflict in your stories?