In Game Of Thrones, when someone is on trial for something the accused has the option of choosing "trial by combat" instead of an actual trial. In this the they (or someone fighting on their behalf) fight someone (chosen by the prosecution) to the death. I think the idea being that the gods then let them live, or not, based on their guilt.
Is this concept based on, or at least inspired by anything historical?
You may be interested in this previous question on the topic.