(Why is the image for this post Jaws? Because it’s the top Google Image result for “diegetic” with size==large. That’s why.)
A month or so ago I heard a new RPG theory term: diegetic. Apparently it’s actually been in use for years (I can find records going back at least to 2008) and appears to have originated in the Nordic LARP scene. The context that it came to me with was a recent resurgence in use of the term with the OSR crowd. Here’s the wikipedia definition:
“Hit points [...] are not themselves part of the narrative situation.” Huh. I don’t think it’s as simple as that.
Hit points establish a fact within the world of the game. The diegetic world. A person with their full allotment of HP is unharmed. A person below their maximum HP is in some way hurt or worn down.
Of course some of that depends on the definition of HP within a given system. Let’s take the d20 SRD definition to turn this into a concrete example:
Both of these things are diegetic: they exist within the world of the game. They may not immediately be physically obvious, but they likely are. The GM might describe a soldier with full HP as looking “fresh, rested, and ready to go.” A few HP and the soldier’s “worn out and beaten up, panting for breath.”
Put another way, while HP may not be immediately observable in the diegetic world, they are testable. Some scientific-minded wizard could come up with this experiment: Hit someone with a warhammer. If they pass out, they had 8 or fewer HP. If they don’t, they had more than 8 HP.1 1. If our wizard was being really thorough he’d increase the sample size to average out strength bonuses, but I doubt many subjects would agree to participating in the study more than once. From there our wizard could, by varying weapons and targets, figure out HP for anything in the world.
Sure, that’s a bit like testing for witchery by drowning, but it does show that HP is something your character can observe. Since there’s a constant tie between the actions of the characters and the rules some things presented in the rules are also present in the fiction.
Of course there are non-diegetic elements in some games. The dice in Fiasco are non-diegetic: the characters have no idea they exist even in an abstract sense.2 2. Though that does suggest a Fiasco playset for characters being messed about by the “gods,” i.e. the dice, system, and players. In that playset the dice could be a diegetic element since the fact that omnipotent beings are shaping the actions of the characters (often for the worse) and that there’s a limit on how much good and bad there is to go around is a part of the fictional world. They couldn’t even really test for them as our science-wizard could test for HP since their assignment doesn’t (necessarily) follow from the character’s actions.
If you’ve seen me play Fiasco it should come as no surprise that I don’t think non-diegetic (mimetic?) mechanics are a bad thing. They’re just one more tool to be used. Apply them to the wrong game and it’s a problem. Apply them the right game and they’re fantastic.
The important takeaway here isn’t about the divide between mimetic and diegetic. The takeaway is that the divide between the world of the characters and the world of the rules isn’t such a clear thing in many roleplaying games. That’s a feature, not a bug.