Note: This might be a bit of a naïve question, but I imagine it is a valid one. I am not a historian.
That is, were there any "standard" activities (with a set of rules or other concrete description), be them board-based or not, that involved acting/role-playing with the intent of mutual entertainment?
Sure, theatrics themselves are very ancient, but are usually intended as a presentation to a public, not for the entertainment of the actors themselves.
So, was any kind of roleplaying game practiced?