When some authority or power dictates what counts as "fighting fair" and actively enforces these rules on the battlefield. Almost always a neutral party in regards to the fighting itself, they exist solely to make sure the rules of battle are followed and punish those who break them. Their presence is often Justified -- if the fighting in question is a Tournament or Blood Sport, for example -- but they'll just as easily show up in real battle-to-the-death combat, in which case their presence may cause large amounts of Fridge Logic. Liberal application of the MST3K Mantra is recommended. Expect an evil or ruthless character to attack the Combat Referee at some point; this may result in the heroes being forced into a no-rules grudge match, or it may prompt the referee to deal with his attack