Henry
Autoexreginated
I really cannot think of or even CONCEIVE of an RPG that does not have a referee, because to dispose of a referee turns it into improvisational theater, or Live Action Roleplay.
Further, RPG's are defined by rules, as you said, but the rules always (ALWAYS to my knowledge) contain a resolution mechanic for actions in which outcome is uncertain, even if such is as simple as "rock, paper, scissors."
Part of the goal of defining RPG's is to define what it consists of, up until this time, and to try and conceive of types of RPG's heretofore unknown may broaden your definition to the point of unrecognizability. So, the presense of a referee and the presence of resolution mechanics are integral parts, in my estimation.
(Of course, most sports from baseball to boxing also have these two elements, but the people are not portraying roles. And wrestling can't apply, because while there are referees and an imaginary world, there are not resolution mechanics for outcomes - just scripts.
)
I hope that my ramblings do not sound overly simplistic, but these two things do figure heavily into the definition of an RPG for the past 30 years.
Further, RPG's are defined by rules, as you said, but the rules always (ALWAYS to my knowledge) contain a resolution mechanic for actions in which outcome is uncertain, even if such is as simple as "rock, paper, scissors."
Part of the goal of defining RPG's is to define what it consists of, up until this time, and to try and conceive of types of RPG's heretofore unknown may broaden your definition to the point of unrecognizability. So, the presense of a referee and the presence of resolution mechanics are integral parts, in my estimation.
(Of course, most sports from baseball to boxing also have these two elements, but the people are not portraying roles. And wrestling can't apply, because while there are referees and an imaginary world, there are not resolution mechanics for outcomes - just scripts.

I hope that my ramblings do not sound overly simplistic, but these two things do figure heavily into the definition of an RPG for the past 30 years.