The Central Mechanic of Tabletop Roleplaying Games

I participated in a discussion about how the game plays in tabletop roleplaying. The following is probably not constructive for the conversation but it does sum of my view of what make RPGs, RPGs, and why they are so different than boardgames and wargames. 

While the following is a specific series of steps, the circumstance they can be applied too is nearly infinite. Also it can turn on a dime if the circumstance the referee describes changes. Whether that change follows from what the player did a their character is sometimes debated but it still implies an inherent flexibility that all RPGs possess. 

Sub Main()
  Setting := CreateSettingAndCampaign(Referee)
  Players := CreateCharacters(Setting)
  Do
       Call RefereeDescribesCircumstance()
       For Each Player In Campaign
             PlayerAction =  DescribeCharactersAction(Player)
             Call RefereeAdjudicateCharacterAction(PlayerAction)
       Next
  Loop Until Campaign = CampaignStatus.CampaignEnds
End Sub

Sub RefereeAdjudicateCharacterAction(aAction as CharacterAction)
   Decision = RefereeDecidesAdjudicationProcess(aAction)
   Select Decision
        Case DecisionType.Failure
             Call RefereeDescribeFailure()
        Case DecisionType.Success
             Call RefereeDescribeSuccess()
        Case DecisionType.Uncertain
             Call RefereeUseSystem(aAction)
    End Select
End Sub