Let's Talk About Core Game Mechanics

[pemerton]

The core mechanic isn't rolling dice; it's the communication between players.

No, that is the procedure of play.

What's the difference between procedure of play and core mechanic??

A "core mechanic" is the system by which the questions that come up in the procedure of play are answered.

There's a lot of variety in RPGs. But most of them have two distinguishing features:

* There is a fiction that the participants imagine together, that matters in game play, in the sense that the shared fiction constrains what moves the participants are able to make, and what follows from those moves.

* The "typical" participant engages the shared fiction from the perspective of a particular character within it: the fiction is presented to them - by the "referee/moderator" participant - primarily as what that character knows and experiences, and they make changes to the shared fiction primarily by saying what that particular character does/​

The first feature distinguishes RPGs (and also some other games, such as some wargames) from more typical boardgames.

The second feature distinguishes RPGs from shared fiction creation games that involve a more "god's eye view" approach to creating the fiction, and from wargames where the "typical" participant controls their forces from a "god' eye" perspective.

Bringing these features together, I would say that the medium of play for most RPGs is a shared fiction that is being engaged asymmetrically: one participant is presenting the fiction to the others as if those others "were there" - and the others are presenting the actions that are undertaken by the characters they control.

The procedures of play are the particular methods that a given game uses to manipulate the medium of play, and make it "go". Just to give two examples:

* In classic D&D, the GM - in advance of actual play - prepares a dungeon, by way of map and key; and the GM then presents this dungeon to the other players, as a place for them to explore and "solve"/"beat" by means of their play of their characters. The most important procedures of play are (i) the players describing where their PCs go, with the GM tracking this on the map; and (ii) the players describing what their PCs do vis-a-vis the architecture and furniture, and the GM resolving this by reference to the key.

* In Burning Wheel, the GM and players - in advance of actual play - establish a background situation together. The GM is expected to contribute the "big picture", while the players contribute their PCs, what their PCs care about, including their PCs' relationships and reputations and affiliations. There is a back-and-forth, iterative aspect to this: a player's decision about their PC's family, for instance, might feed back into the GM's conception of the "big picture". The most important procedure of play is that (i) the GM presents a situation to the players, that draws on the "big picture" and presents some sort of challenge or obstacle to the PC (based on what one or more of the PCs cares about), so that (ii) the players are provoked to declare actions for their PCs, and (iii) those actions are resolved using a moderately intricate dice pool system, with the important upshot of that resolution being (iv) how it changes the situation in ways that matter to what the PCs care about.​

When it comes to mechanics, I think it's helpful to keep in mind that "mechanic" is cognate with "machine". A mechanic is a particular type of process, that tells the game participants what to do next in a machine-like way.

To go back to classic D&D, the rule that when the players open a door in the dungeon, the GM tells them what their PCs can perceive does not set out a mechanic. It just tells the game participants what to do under certain circumstances that will come up in play. But the rule that when a player has their PC try to open a door in the dungeon, the player makes a roll, dependent on their PC's STR, to see if they can successfully open the door does set out a mechanic - namely, the roll to open dungeon doors.

The general effect of a mechanic is to take some of the decision-making out of the immediate hands of (one or more of) the participants, and to "outsource" it to a machine-like process. An important aspect of a game's rules is what it prescribes about how mechanics are to be used. For instance, the AD&D PHB and DMG set out a mechanic for determining whether a PC discovers a secret door if (a) the player declares that their PC searches for secret doors and (b) the GM's map and key indicate that there is a secret door in the immediate vicinity of where the PC is searching. But the DMG also says that the GM is free to not use the mechanic, and instead to adjudicate the declared action via the basic procedure of play I described above (that is, relying on their key to tell the players what happens when they have their PCs do stuff to the architecture and the furniture). This contrasts with (say) the rules for Burning Wheel, which say that when a player declares an action for their PC, which pertains to something that their PC cares about, the dice must be rolled: in those moments of play, the rules expressly forbid determining the outcome simply by one or more participants narrating what happens next as a result of what the PC is doing.

To a significant extent, it is all these differences in procedures of play that permit such a variety of experiences to result from the use of the same medium of play. Differences in procedures of play aren't all that matters to the experience of play. But they are a big part of it.

 

[pemerton]

An issue with skills in many RPGs is that they rely too much on random chance. Linear systems feel particularly prone to this, but other types of systems can also have that problem.

Basically, in real life most people have a number of things they can do reliably. There are also a number of things I know I can't do, and some things I might be able to do. Someone who's more experienced in a particular field has more things they can do reliably, and they can probably do the basics faster and better than a newbie. But there are very few tasks where one person would have, say, a 50% chance of success and another more skilled person would have a 70% chance.

I think this is an important question about a core mechanic: what does the outcome of the mechanic tell us about the fiction?

@Staffan's post assumes that the result, in the fiction, of the player failing their roll is that their PC fails to perform the task that they attempted. But that's not the only possibility. Going right back to one of the earliest mechanical systems in RPGing - the "alternative combat system" in original D&D - a failed roll doesn't mean (or at least doesn't necessarily mean) that the PC failed at what they attempted. That is, a failed attack roll might mean that, while the strike was swift and deadly, the opponent is just as puissant and dodged at the last moment. That is, a series of failed attack rolls in D&D can be imagined as looking like the duel in The Princess Bride as much as like a comedic pantomime performance.

It's eminently possible for a RPG to take a similar approach to non-combat resolution.

My general preference is for the player to roll both offense and defense, although the GM can roll the magnitude of the effect. GM rolls for damage, and the player rolls to dodge/block/endure some or all of the effect.

But merging "confirm attack, then roll damage" into "how effective is the attack" just seems like a good way to smooth out table operations. And using different dice and special dice mechanics can still provide texture to different types of attacks.

I've often been puzzled by the notion that modern D&D has a uniform resolution system, when it clearly doesn't: there is no analogue, in the 3E and 5e non-combat resolution systems, to the crucial place of the damage roll vs the hit point total in combat; and thus, while a low-level PC might have a modest-to-slim chance of climbing the wall that present little obstacle to the high-level PC, they have no real chance of surviving a fight with a pit fiend.

And in 4e D&D, while successes/failures in a skill challenge are somewhat analogous to the tracking of hp loss, the skill challenge and combat resolution systems are still clearly different. The game relies on mechanical components of creature stat blocks - defence numbers, hit points totals and damage dice - to mark the difference between fighting a kobold and fighting a pit fiend - while it relies on the more abstract interplay of the tiers of play and the DCs by level table to mark the difference between the non-combat endeavours of low- and high-level characters.

There are plenty of RPGs that are more uniform than these versions of D&D, but plenty of these still treat combat outcomes in a distinctive way - eg harm in Apocalypse World, or wounds in Burning Wheel. Some RPGs I can think of that are strictly uniform are Agon 2e, Cthulhu Dark, and Marvel Heroic RP (although this last one still has many more abilities on the typical PC sheet that feed into physical conflict than feed into social/emotional conflict).

 

[Thomas Shey]

I think this is an important question about a core mechanic: what does the outcome of the mechanic tell us about the fiction?

@Staffan's post assumes that the result, in the fiction, of the player failing their roll is that their PC fails to perform the task that they attempted. But that's not the only possibility. Going right back to one of the earliest mechanical systems in RPGing - the "alternative combat system" in original D&D - a failed roll doesn't mean (or at least doesn't necessarily mean) that the PC failed at what they attempted. That is, a failed attack roll might mean that, while the strike was swift and deadly, the opponent is just as puissant and dodged at the last moment. That is, a series of failed attack rolls in D&D can be imagined as looking like the duel in The Princess Bride as much as like a comedic pantomime performance.

It's eminently possible for a RPG to take a similar approach to non-combat resolution.

I've argued this should be something that is considered in virtually any system that has a randomizer in it (though in situations with opposed rolls in systems using those, its easier for people to conceptually engage with). After all, what does that randomizer represent? I'd argue a variety of factors too small for the GM to supply as part of the narrative up-front, and some of those are going to be things a character has no control over. If an attacker turns his ankle on a pebble during an attack, throwing him off, is that his fault or just the fault of living in a world you don't entirely control?

There are plenty of RPGs that are more uniform than these versions of D&D, but plenty of these still treat combat outcomes in a distinctive way - eg harm in Apocalypse World, or wounds in Burning Wheel. Some RPGs I can think of that are strictly uniform are Agon 2e, Cthulhu Dark, and Marvel Heroic RP (although this last one still has many more abilities on the typical PC sheet that feed into physical conflict than feed into social/emotional conflict).

Well, I'd suggest that still has to do with the perception (whether always true of not) that the consequences of failed combat are both central to a lot of what's going on, and potentially more permanent than the other sorts of things on a routine basis.