Why do RPGs have rules?

[Maxperson]

Can you please cite for me where in the AD&D rulebooks the term "rule zero" is found? I'm fairly familiar with those books and don't recall it.

EDIT:
I must have become confused about what you were suggesting - ie that you were suggesting it was called "rule zero" during AD&D - because you said "1e is where the term comes from." That made me think that you were suggesting that 1e is where the term came from, which in turn made me think that you were saying that the term "rule zero" was used in AD&D.

Yeah. I was just pointing to 1e as the first edition that I can recall where the concept was present. It was later dubbed Rule 0.

 

[FormerlyHemlock]

If it's not unilateral, then he is not THE authority. It's built into the way it reads.

The DM can and should listen to the players if they disagree. So the players can dispute it that way. If the DM holds fast, though, the only further way to dispute the change is to leave the game. The players have no authority to change a rule against the DM's wishes.

It would be interesting to see what happens at a table where players selectively ignore the GM's statements.

GM: Bob, the cyclops throws a building at you. Take 20d20 damage. [Rolls] 234 damage. You're an ink strain on the rock.

Bob: That's not fair. I have Blink. [Rolls] I teleport 15' out of the way instead. The building smashes itself uselessly to pieces beside me.

GM: No you don't. It hits you.

Alice: Bob, cast Great Haste on me so I can blenderize the cyclops.

Bob: Okay. [Rolls] Success! You're great Hasted.

Alice: I run over and stab him in the eye, twice! [Rolls] One hit! GM, does he Dodge?

GM: None of that happens. Bob is dead.

Alice: No, he teleported out of the way with Blink and then Great Hasted me.

Bob: Yeah.

Feels like a Knights of the Dinner Table comic strip honestly. There's a decent chance the GM knuckles under and Bob lives (especially if the GM ruling was ill-founded).

 

[pemerton]

Clearly you get the point of the definition I'm using, but reject it because you dislike the implications (including for 5E). There's nothing more for me to say beyond, "no really, that's what I mean when I say RPGs are not complete in the same sense chess is: there's no uniquely determined next game state until the GM steps in to provide one."

In chess there's no uniquely determined next game state until a player steps in to provide it (ie by choosing a move).

 

[pemerton]

these are 2 different properties of games! Complete/Incomplete is telling us whether there are instructions (IE procedural rules) covering all situations which may arise within the game state. I contend that Dungeon World has this form of completeness. No matter what the fictional state is, we have a rule which tells us how to proceed.

Open/Closed is a separate question. Open games have an infinite possible set of game states, such as RPGs. Closed games have finite states, like Chess. All closed games can potentially be made complete by the application of enough rules. I mean, maybe there's a 'halting problem' here where you can construct a game who's states cannot all provably be reached or something...

<snip>

a Complete but Open game can be structured by using a simple general rule which has the property of closure, that is you can chain (or nest, I won't go into how these are equivalent) the output of one application of such a rule into the input of the next. RPGs of this sort, like DW, then typically employ exception based design to allow the addition of a richer set of tools without breaking the system's complete nature.

The non-RPG games that I mentioned upthread that have, in practical terms, an unlimited number of possible game states are typical field sports.

I'm saying this based on the idea that there is no effective limit on the number of possible field positions, nor on the way these can combine with the range of possible score states (and obviously, a captain sets the field in response, in part, to the score).

This doesn't mean that the rules for a field game are necessarily incomplete. There can be the occasional rough edge, but I don't think that many (eg the underarm bowling incident was controversial from the point of view of fair play, but not from the point of view of permissibility with the rules).

 

[pemerton]

I cannot imagine why you are telling me this true but immaterial fact. Did you think I said otherwise? I did not. Player action is an input to the game state transformation function (function: mapping of input to unique output).

If this fact is immaterial, why are you citing the GM - a player of the game - making input into the game state as if it shows the rules are incomplete?

 

[pemerton]

The DM can and should listen to the players if they disagree. So the players can dispute it that way. If the DM holds fast, though, the only further way to dispute the change is to leave the game. The players have no authority to change a rule against the DM's wishes.

The GM has no unilateral authority to change a rule against the players' wishes either. Because if the players all leave the game, there was no rules change - the GM at that point is not playing a game by their preferred rules; they're failing to play the game they hoped to be playing.

 

[FormerlyHemlock]

In chess there's no uniquely determined next game state until a player steps in to provide it (ie by choosing a move).

I say, "In chess, XYZ."

You say, "In chess, XYZ." But you say it as if you think you're contradicting me. What's up with that.

I'll try one more time: in chess, if rules(state, move) is a function returning state'. Notice that move is an input to rules. For example, given the state "white has taken one move, pawn to e4; black's turn", and the action "black moves pawn to e5", the new state is "white has taken one move, pawn to e4; black has taken one move, pawn to e5; white's turn".

You keep pointing out to me that move is an input to rules as if I were somehow ignorant of that fact. Do you have an actual point?

If this fact is immaterial, why are you citing the GM - a player of the game - making input into the game state as if it shows the rules are incomplete?

I'm citing the GM because my whole point is that rule(state, action) => state'. If you agree that rule in an RPG requires occasional GM input because the rulebook's rule is only a partial function (some actions are unmapped), congratulations, you agree with my point.

 

[pemerton]

You keep pointing out to me that move is an input to rules as if I were somehow ignorant of that fact. Do you have an actual point?

You (and @clearstream) keep pointing out this about DW as if it shows that DW is incomplete.

My point is that you (and clearstream) are therefore deploying contradictory notions of completeness.

 

[pemerton]

want to make sure I know where you're coming from on the idea of new rule-like things that still don't count as rules. Since I'm not familiar with Dungeon World terminology, could we examine the same situation (opening a sewer hatch) from the perspective of AD&D to see if these also don't count as rules in your eyes, or if there's something special and different about Dungeon World?

Player wants to open the sewer hatch. DM specifies Open Doors roll at -2 to pull open. Player fails. Ties a rope to the sewer hatch, sets up a pulley system as a force multiplier. DM allows this to give a +6 bonus on the Open Door roll but says that if it fails then that means the rope snapped. Player succeeds and DM gives them a 50% chance of being drenched in sewer water spraying out of the hatch (they roll 2 on a d6 and do get drenched) but this turns out to be a valid back door into the area where the princess is being held hostage.

Same scenario as the Dungeon World custom move for sewer hatches quoted above. Same degree of reasonable extrapolation to cover scenarios not spelled out explicitly AFAIK in the AD&D rulebooks (pulleys and rope strength; probability of getting drenched by a nearby liquid steam).

Here's the difference:

In DW, there is no need for a custom move to adjudicate opening a sewer hatch. If a player declares "I open the sewer hatch*, the rules tell everyone what happens next: the GM makes a move. The rules also tell us whether that is required to be a soft move, or permitted to be a hard move.

The custom move is not needed to adjudicate this action declaration. It is something that the GM has added in - as @AbdulAlhazred has noted, analogous in D&D to a distinct random encounter table; or, as I noted, analogous to detailing some property of the room (like "anyone crossing this muck-filled room must make a DEX/reflex save to avoid falling into a concealed pit of filthy water"; or "anyone crossing this muck-filled room has a 2 in 6 chance of stumbling into the gelatinous cube that sits in one corner of it").

 

[Maxperson]

The GM has no unilateral authority to change a rule against the players' wishes either. Because if the players all leave the game, there was no rules change - the GM at that point is not playing a game by their preferred rules; they're failing to play the game they hoped to be playing.

That isn't at all true. The DM is fully capable of going to get other player to play by those rules. The rules change still happens.