What is the purpose of rules in an RPG? Like individually, what do they do? On one level they define the reality of the fiction, if you know what I mean. For players to make decisions, formulate plans, and help imaginary communities (or whatever your story is about) the fiction needs to be consistent. Rules help do that. The army moves at most 3 hexes per day, so we can reach the bridge first! I am smart and charming, so I can probably convince the foreman that we need access to the worksite. The village needs a wagon of grain and a dozen chickens to see it through winter.
But rules also take away agency from both players and GMs. As a player you might want to swing on a chandelier, land on the vizier, cut the princess free and jump out of the window, but the initiative system and the requirement for you to make a bunch of good rolls both stop you doing what you want. The initiative system is there to ensure the spotlight is shared between all PCs; it also helps with consistency of the fiction but having time affect all actors roughly the same. GMs are also bound by the rules, they must pass rolls for their NPCs, their NPCs can’t walk through walls, unless there is a specific exception. Clearly GMs can just ignore this is they want, some GMs are comfortable just making anything happen if it makes a good story, or if it is something which they could have prepped for if they had known what was coming… That might be a different conversation though.
So we have rules which provide structure to the fiction, and rules which provide balance between players at the table. I can think of a few others.
There are rules which provide interesting situations for PCs to deal with. Random generators mostly. Wandering monster tables, rumour tables, seasonal weather generators… Maybe Pendragon’s Winter phase or the Engagement roll in Blades? These are rules which add stuff to your game (I was trying to avoid using the ‘g’ word – no one can agree what it means) maybe to add challenge or to increase verisimilitude or just to stop the world feeling like it is all the work of one person.
Then we have rules which skip things we don’t want to spend time on. PCs need to eat 1 ration per day. We don’t care what they are eating, or if they are hitting their RDA of vitamins and iron, we are interested in whether they are starving or not and the rule lets us skip to that information. When populating a dungeon we don’t have time, or honestly, the ability, to figure out the entire history of this collection of tunnels, so we instead roll random inhabitants and figure out a justification if we want one. A hacker PC wants to find information on someone, we don’t need to know which systems they hack or how they get through security, they roll on hacking, and we get on with the story.
These rules abstract away the things we don’t want to spend too much time on, but is that maybe true of all game mechanics? Pendragon’s winter phase moves us quickly through the cold miserable months to the next adventure. The engagement roll in Blades skips the slow, safe parts of the heist where nothing much happened. Wandering monsters mean GMs don’t have to know where all their monsters are, skipping that bookkeeping. To-hit rolls are the end point of your cool combat move: did it work? We don’t want to sit at the table trying to figure out if a diving tumble and an upward stab with a rapier would actually work, it sounded cool, now roll a d20. Initiative systems let us skip the five-way discussion about who’s paying attention, who’s closer, who has an arrow nocked or who has the longer reach. Combat is chaotic, roll initiative and get on with it.
This isn’t all my own thinking, Jared Sinclair and Luke Gearing got me started. They call it “rules elide”, although I don’t think I’ve ended up at the same place conceptually as they are at. It’s taken me a few weeks to get my head around the implications. For one thing, there are so many different aspects to an RPG in motion that, as shown above, there are many ways that rules can guide you through the fiction as you play.
I think the hacking example above is relevant here. It’s not true that all tables will want to skip the details of the hacking. In a cyberpunk RPG the details of the hack might be the climax of the whole session. The group have gathered fake biometric ID for staff and some military grade cracking software, and the hacker has been training on this type of security system; now we want to know how each of these items interact. At least to a certain extent. Maybe we have a rule for fake biometric ID vs card reader, we don’t need to know how the card reader works as this is still all make believe, but maybe we chose to have a roll to determine how long it takes, to build up the tactical considerations of the infiltration. Maybe the hack itself is a few rolls to get through each layer of the system, so the game is eliding what actually “hacking a layer” means, but it’s adding colour to the process (see Die Hard for a cinematic example). Or, the hack could play out like a combat, the hackers rolling attacks and trying to deplete the HP of the system. There could be tactical considerations, special attacks, armour, defence… (This one is clearly Tron) Again, the rules elide the technicalities of the actual attacks, but we’ve gone deeper into the fiction before the rules bring us back up.
I picture a game session as a line of events from where it starts to where it finishes. Like any work of fiction, the amount of detail varies depending on what we are interested in. We dig deeper into parts which matter more adding facts and complications and when we have gone deep enough our rules cap off that descent into minutia and bring us back up to the next round, encounter or scene.
I don’t think “rule elide” is all mechanics do, but I do agree that every rule is eliding something, so when I’m writing mechanics I’m going to try and make sure I know what options I’m closing down, what agency is being withheld and what part of our shared fiction I just elided with a dice roll.