Quits when losing, as the others have said, but fortunately he doesn't really understand what a losing position is. He was only down five troops and had the first turn advantage (usually first to get a set), and he was favored to break into SA (which I had conquered) had he tried... but instead he just gave up and gave me the easy points! Can't complain about that :)

Quite when losing rather than taking a few minutes to burn his turn like any decent person would, says a lot about a person.