Designer’s glossary: Narrative mechanics (TTRPG)
[ˈnær ə tɪv məˈkæn ɪks], [nar-uh-tiv muh-kan-iks]
A bridge between the events that characters within the game are experiencing and the narration of said events by the players. Narrative mechanics are definitions for triggers that get activated when something happens in the narrative being described, linking that event to concrete game mechanics that can create the output needed for the system to process and evaluate the interaction.
Important to note: Narrative mechanics are not pertinent to the popularly-referred-to-as “narrative games”, since those attempt to forego the usage of as many mechanics as possible.
What makes narrative mechanics distinct from classical mechanics is how they are engaged with by the players. Classical game mechanics are explicit – they are actively engaged with by player choice (note that this doesn’t prevent them from having a specific narrative requirement or consequence). Whereas as narrative mechanics are implicit – they automatically get engaged with based on what happens in the narrative, though due to the nature of the tabletop medium, they still require a player to look out for the trigger so that it can happen.