Introduction

The release of 1st edition AD&D was the coming-out event for the hobby of roleplaying games. Thousands of people across the nation played the game -- including many future game designers. The game's influence on these future designers was deep, and the influence of AD&D on their designs was lasting. Many of those influences would be shaken off in later generations of games. Because AD&D sits firmly in the Gamist-Simulationist corner, it is the Gamist and Simulationist game designers that have had the most difficulty shaking off its influence. AD&D gave the Narrativist game designer no basis to build upon, so Narrativist designers were forced to build from scratch. It is the purpose of this essay to examine one of the most enduring legacies of that game: the focus of attention during game play on the dice.

Dice Primary vs Skill Primary

In contrast to most modern games, AD&D came with a plethora of different mechanics. It seemed that each skill had its own mechanic. But most of these mechanics fit into a single category: based on the character's ability, the character has a target number of some kind. In order to succeed, he must roll above or below that target number. In terms of actual game flow, this generally amounts to first calculating the target number and then rolling the dice. This emphasizes the dice in the resolution mechanism. By this, I mean that the resolution mechanism _psychologically_ relies upon the dice as the arbiter of resolution. It is the dice themselves that finally determine the result -- and that is how the players tend to perceive it. This legacy of AD&D has been continued in nearly every roleplaying game. The slur "roll-playing" has a certain kernel of truth to it: when playing these games, the players often feel as if the dice themselves control their characters' destinies. I call these resolution mechanisms "Dice Primary".

Contrast this with the FUDGE model -- where the resolution mechanism places the character's skill (and gamemaster judgement) in the driving position, psychologically. The dice roll is centered about 0, and added to the character’s skill. To the players, the dice appear to represent those “random” factors which cause performance variation. Importantly, the dice roll is seen as a modifier to the character’s skill, and this connection is quite transparent. The modified skill level is used by the gamemaster to determine the adjudication. This method tends to make the character’s skill the primary factor in the resolution, in a psychological sense. Even if the resolution mechanism is mathematically the same as a Dice Primary method, a Skill Primary method highlights skill rather than dice.

FUDGE's influence in this regard has been quite minimal with respect to Gamist or Simulationist designs, perhaps because it's primary appeal is to a different crowd. As a dyed-in-the-wool Simulationist, I find this unfortunate – as I believe Dice Primary methods have significant disadvantages.

Thinking About Target Numbers

The first advantage of Skill Primary systems is that they aid the gamemaster in constructing Target Numbers (TNs). The difference is in how the two types of systems ask the gamemaster to think about TNs. A Dice Primary game typically asks the gamemaster to place the task in one of several difficulty levels. This difficulty level then determines the target number. Unfortunately, at no time is the gamemaster encouraged to ask himself the question 'how skilled should a character be to have even odds of success and failure?' but instead is asked the question ‘how would you classify this task on the scale Easy, Moderate, Hard, etc. ?’ I believe that the former question is a more useful way to think about target numbers. I believe that through intuitively relating the target number to character skill levels, the gamemaster is presented with a natural and compelling way to think about target numbers. However, Dice Primary game designs discourage this way of thinking about target numbers.

Dice and the Game World

The second, and greater, disadvantage of Dice Primary systems is that they disconnect the dice roll from game world events. To begin, let us examine what those dice represent in a Simulationist game. For the game to qualify as Simulationist, the dice must represent something inside the game world. Otherwise they should not be used at all. Commonly, what the dice represent in the game world are the numerous micro-scaled factors which effect task performance. Informally termed “luck”, these factors are too small to have an effect individually, yet have a macro scale effect in toto. For a Simulationist game, the game mechanics should make it apparent what the dice represent: the whole point of such a game is that the adjudication is driven solely by events in the game world. It should be obvious to the players that this is the case.

I submit that Dice Primary methods obscure this connection, in two ways. First, the attention that they place on the dice itself obscures the connection. Secondly, they encourage game designers to use dice distributions with no connection to human task performance data. The obvious flaws in these distributions in turn encourage the players to believe that the dice do not represent an in-game factor. It’s a vicious circle, and it begins with the game designer failing to ask himself the questions ‘is the variation inherent in my dice method scaled appropriately to my skill level numbers, given what we know about human task performance?' and 'does the distribution I am using match the distribution of human task performance?' and 'does the distribution I am using handle boundary conditions in a particularly unrealistic manner?'

At least for Simulationist games, these would seem prima facie to be important questions. But very few game designers seem to have given any of them more than a cursory glance. Perhaps Simulationist game designers do indeed ask themselves these questions, only to determine that the problems are too hard to solve and/or that the traditional answers are good ones. The most well-known innovation in dice mechanics is dice pools; other innovations such as FUDGE dice and “die minus die” mechanics have lagged in popularity. Dice pools are more of a Gamist design than a Simulationist one, and this is apparent in the games that use them. Their distribution changes shape and relative variance with the size of the pool. They generally have boundary condition problems. They also make the determination of sensible Target Numbers a task only for the mathematically talented. Their large handling time tends to focus the game on the counting of successes – ie, on the dice.

Let us revisit the three questions above about the distribution of human task performance. These are routinely ignored by game designers. As a result, games routinely possess ridiculous models of human task performance. These models are not only absurd to a mathematically sophisticated critic --- but they are so out of balance that any intelligent observer will find that their intuition is often at odds with the results of the game's performance model. Commonly, this is because the variation in the dice method is much too high, and it is apparent that the dice roll is weighted more strongly than should be the case. This reinforces the impression that events are resolved based on "dice, modified by skill" rather than "skill, modified by ‘luck’." Another common problem is that boundary conditions result in hacked rules (if using 2d6, 2 always fails, 12 always succeeds, etc.) to avoid automatic successes or failures. The hacks themselves always result in idiosyncracies -- such as additional penalties/bonuses having no effect on the chance of success. These idiosyncracies encourage “playing the system” and strengthen the impression that the resolution’s basis is “dice, modified by skill”.

From a Simulationist perspective, I have to decry these effects. They are unsuitable for a pure Simulationist game, where the focus of the game should be on in-world events. They do often suit the Gamist side of the Gamist-Simulationist corner where these mechanics originated.

Looking Forward

All of this raises the question ‘what can we do to alleviate these problems?’ What properties in a dice mechanic will improve the situation?

First, the mechanic should have a very low handling time. A mechanic which has long handling time will increase the attention given to the dice, subjectively increasing their importance in the resolution system. Low handling time will keep the game’s focus on events in the game world.

Second, the system should be a smoothly opened-end bell curve with no boundary conditions. This is the type of curve which human task performance shows. Matching real-world performance data will make the game’s resolution mechanism more believable.

Third, the dice mechanic should be seen as a modification to character skill, which represents the effects of “luck.” This is well-served by a distribution centered about zero, which sometimes is a benefit and sometimes is a penalty. The dice mechanic should also be scaled so that usually skill dominates over luck.

Finally, luck should be more important in the short term than in the long term. This means that long-term tasks should have a smaller luck factor than short-term tasks. To do this, we must be able to scale our mechanic’s degree of variation.

Two mechanics meet these criteria: FUDGE-like dice and “die minus die” mechanics.

FUDGE-like dice can be made from dice other than d6’s, to meet the needs of games with smaller grain size. For example, 12-sided dice with 6 blank sides and one side labeled each of: +1, -1, +2, -2, +3, -3 will create a smooth bell curve if used appropriately. For example: roll 3 of these dice, and roll one more die if all dice are of the same mathematical sign. Keep rolling an extra die so long as the same mathematical sign occurs. This method can be scaled to more or less variation by rolling more or fewer dice.

“Die minus die” mechanics work by rolling two dice of the same size, and subtracting one die from the other. These can be made to open-end fairly smoothly by awarding an extra die when a maximum value is rolled. The variation can be controlled by varying the size of the dice rolled. This method produces a curve that is less bell-shaped than that of most FUDGE-like dice. This can be improved by rolling a neutral third die, which replaces the lesser of the other two dice if the neutral die’s value is greater.

For games with a pure Simulationist ethic, these are excellent choices. I would like to see more games use them, and any other mechanics which may meet the above criteria. I have been using the first of these methods with satisfaction for years now. The method has been successful in meeting my goals; I had one ex-player comment that he didn’t like my game system because “the dice don’t count for enough.” It was music to my ears.

H'm,

Interesting, Lee. I think - at first glance - that one angle that seems to be missed is the role of dice as they relate to players, rather than to characters' abilities ("skills" as you call them).

If a game's system operates such that the dice apply mainly to the players' privileges (e.g. narration rights, character effectiveness, and more), then dice-rolling becomes exceptionally powerful for Narrativist purposes. Many such games are Dice Primary in your terminology.

At its most radical, you get games like The Pool, in which the Pool owned by each player only exists at the metagame level, and placing more or less dice from one's Pool into one's roll (increasing the chances of success) means literally nothing regarding what the character is using, doing, feeling, or anything else.

Closer to the traditional model, when you apply this system to "events in the game world" in a character-ability way, you get what I call Fortune in the Middle, which is exemplified in games like Hero Wars and InSpectres. (These games also include a certain degree of Skill-ness in your terminology, but not to the extent of say, GURPS or Fudge.)

Other games to check out in this regard include Otherkind, Dust Devils (OK, cards not dice, but big whoop), and Universalis.

Best,
Ron

Thanks for the pointers, Ron.

I'd intended the essay to really only apply to Sim games, and evidently didn't make this clear enough. I should probably have been more clear about that in the introduction.

Lee

Hi Lee,

Ah! Simulationist games, then? H'm, this will be an interesting discussion.

Dice in Sim games ... OK, historically, they've mainly been all about the "game-world physics" in the broadest sense, specifically reinforcing the real-world observation that doing Thing X does not always result in Thing Y, but usually clusters about Thing Y in some way from event to event.

Let's consider more limited aspects of play than "task resolution" or even "to-hit" rolls, which would be pretty broad. I'm thinking ... the degree that armor protects its wearer. Nice focused topic.

1) In most games, armor protects its wearer to a very fixed extent. It often follows the model set by The Fantasy Trip, Tunnels & Trolls, and early BRP (specifically RuneQuest), in which damage is calculated as a value of some kind, and then armor subtracts a fixed amount from the damage.

For games that follow this model, it interests me that so few introduce variation into this effect - only Stormbringer, if I recall correctly, actually introduced a roll to diminish the damage; if you wore plate mail, you rolled d8 or maybe it was d12 to see how many points were deducted from the axe's rolled damage to your character's tender flesh. I suspect that in these games, the desire to see "variability" in action was hitting a limit of handling time, which in games like Stormbringer (a BRP variant) was already considerable.

In other words, quite a few Sim games diminish the Dice-Primacy of protective values.

The other most-common system, set by D&D, decreases the attacker's chance to do damage in the first place (prior to a "damage roll"); this is what THAC0 is all about. This method tends to increase search time rather than handling time, but it also incorporates the (possibly desirable) variability in automatically.

I suggest that such systems tend more toward the Gamist end of things, especially that brand of Gamism that encourages a high random factor during play. (Damn! Must check Ninja Burger when I dig it out of the moving boxes; that's a pure Gamist random-heavy romp.)

One problem with generalizing like that, though, if that versions of D&D represent a non-independent cluster of design, which cuts down significantly on the available number of instances to consider. I don't know how Rune handles armor; can anyone help with that - is that a randomized variable? As a side note, I do think that Stormbringer, mentioned above, was a very Gamist slant on BRP (Ken St. Andre was the author, a dedicated Gamist in design terms).

But that's just one topic out of many. Anyone else want to pick some aspect of events-during-play that can be broken down into its Dice-Primacy status, for a given game or maybe how it's changed across games?

Best,
Ron

Great article Lee! I have a few problems with some of it, merely semantic quibbles for you to clear up.

Lee Short wrote: Dice Primary vs Skill Primary

...based on the character's ability, the character has a target number of some kind. In order to succeed, he must roll above or below that target number. In terms of actual game flow, this generally amounts to first calculating the target number and then rolling the dice. This emphasizes the dice in the resolution mechanism.

...I call these resolution mechanisms "Dice Primary".

the resolution mechanism places the character's skill (and gamemaster judgment) in the driving position, ...the dice appear to represent those “random” factors which cause performance variation. Importantly, the dice roll is seen as a modifier to the character’s skill, and this connection is quite transparent. The modified skill level is used by the gamemaster to determine the adjudication. This method tends to make the character’s skill the primary factor in the resolution,

...a Skill Primary method highlights skill rather than dice.

Lee Short wrote: ...Dice pools are more of a Gamist design than a Simulationist one, and this is apparent in the games that use them. Their distribution changes shape and relative variance with the size of the pool. They generally have boundary condition problems. They also make the determination of sensible Target Numbers a task only for the mathematically talented.

Lee Short wrote: First, the mechanic should have a very low handling time. A mechanic which has long handling time will increase the attention given to the dice, subjectively increasing their importance in the resolution system. Low handling time will keep the game’s focus on events in the game world.

Lee Short wrote: Dice and the Game World

For the game to qualify as Simulationist, the dice must represent something inside the game world....

...Secondly, they encourage game designers to use dice distributions with no connection to human task performance data. ... ‘Is the variation inherent in my dice method scaled appropriately to my skill level numbers, given what we know about human task performance?' and 'does the distribution I am using match the distribution of human task performance?' and 'does the distribution I am using handle boundary conditions in a particularly unrealistic manner?'

...Matching real-world performance data will make the game’s resolution mechanism more believable.

Hey Fang,

Quick Moderator justification thing.

I'm happy with this thread in RPG Theory. It's utilizing GNS terms but not debating or clarifying them as a topic. The main issue is dice/randomizing, seems to me.

Also, what do you think if we specify to Simulationism, sub-set Exploration of System? That covers a huge range of existing RPGs and permits us to focus on things like "learning to pick locks," "taking damage from falling," "convincing the barmaid to perform oral sex on your character," and "hitting that guy with an axe."

Best,
Ron

With regards to the first part of your post Fang, I think *appearances* are exactly what Lee was talking about.

The presentation of the "Dice central" mechanics draws the players attention to the dice as the primary factor to be concerned with.

The presentation of the "Skill central" mechanics draws the players attention to the characters abilities as the primary factor to be concerned with.

I don't think you'll find many actual significant mechanical difference (the illusion of FUDGE's adjective based system has been discussed many times). But I do think that the PERCEPTION by the players during play can be very different.

I suspect this is mainly an issue when dealing with immersive play techniques where having mechanics that present skills first is less jarring than mechanics that continually draw attention to the dice.

I have to disagree about FUDGE putting primacy on skills. Maybe it is in the text, but in actual play, the dice are terrifically variable; perhaps one of the most common topics on the mailing list, if not the most common, is how to mitigate a really evil "whiff factor."

--JB

First Lee, good essay. That is, I love to see this sort of criticism (I do it myself a lot). But, I don't see this as nearly the issue you make it out to be. I'll address your points below, as they are numerous. I will say before hand that my attitude may be a bit caustic sounding, but it's not meant that way. Also, I do have the advantage of having been here a while, so I hope I don't come off as elitist. Please try to see it as an honest criticism of your (well-written) comments.

I will point out first (and I can't believe that Ron didn't mention this at all), for reference that use of dice and all randomizers falls under what is referred to as Fortune mechanics (from a Tweet essay, IIRC). But this does specifically address dice, and I will try to stay on target there.

Lee Short wrote: AD&D gave the Narrativist game designer no basis to build upon, so Narrativist designers were forced to build from scratch.

Contrast this with the FUDGE model -- where the resolution mechanism places the character's skill (and gamemaster judgment) in the driving position, psychologically. The dice roll is centered about 0, and added to the character’s skill. To the players, the dice appear to represent those “random” factors which cause performance variation. Importantly, the dice roll is seen as a modifier to the character’s skill, and this connection is quite transparent. The modified skill level is used by the gamemaster to determine the adjudication. This method tends to make the character’s skill the primary factor in the resolution, in a psychological sense. Even if the resolution mechanism is mathematically the same as a Dice Primary method, a Skill Primary method highlights skill rather than dice.

FUDGE's influence in this regard has been quite minimal with respect to Gamist or Simulationist designs, perhaps because it's primary appeal is to a different crowd.

The first advantage of Skill Primary systems is that they aid the gamemaster in constructing Target Numbers (TNs).

I believe that through intuitively relating the target number to character skill levels, the gamemaster is presented with a natural and compelling way to think about target numbers. However, Dice Primary game designs discourage this way of thinking about target numbers.

To begin, let us examine what those dice represent in a Simulationist game. For the game to qualify as Simulationist, the dice must represent something inside the game world. Otherwise they should not be used at all.

Commonly, what the dice represent in the game world are the numerous micro-scaled factors that effect task performance. Informally termed “luck”, these factors are too small to have an effect individually, yet have a macro scale effect in toto.

For a Simulationist game, the game mechanics should make it apparent what the dice represent: the whole point of such a game is that the adjudication is driven solely by events in the game world. It should be obvious to the players that this is the case.

I submit that Dice Primary methods obscure this connection, in two ways. First, the attention that they place on the dice itself obscures the connection.

Secondly, they encourage game designers to use dice distributions with no connection to human task performance data. The obvious flaws in these distributions in turn encourage the players to believe that the dice do not represent an in-game factor. It’s a vicious circle, and it begins with the game designer failing to ask himself the questions ‘is the variation inherent in my dice method scaled appropriately to my skill level numbers, given what we know about human task performance?' and 'does the distribution I am using match the distribution of human task performance?' and 'does the distribution I am using handle boundary conditions in a particularly unrealistic manner?'

At least for Simulationist games, these would seem prima facie to be important questions. But very few game designers seem to have given any of them more than a cursory glance. Perhaps Simulationist game designers do indeed ask themselves these questions, only to determine that the problems are too hard to solve and/or that the traditional answers are good ones.

Dice pools are more of a Gamist design than a Simulationist one, and this is apparent in the games that use them.

Their distribution changes shape and relative variance with the size of the pool. They generally have boundary condition problems.

They also make the determination of sensible Target Numbers a task only for the mathematically talented.

Their large handling time tends to focus the game on the counting of successes – ie, on the dice.

From a Simulationist perspective, I have to decry these effects. They are unsuitable for a pure Simulationist game, where the focus of the game should be on in-world events. They do often suit the Gamist side of the Gamist-Simulationist corner where these mechanics originated.

First, the mechanic should have a very low handling time. A mechanic which has long handling time will increase the attention given to the dice, subjectively increasing their importance in the resolution system. Low handling time will keep the game’s focus on events in the game world.

Second, the system should be a smoothly opened-end bell curve with no boundary conditions. This is the type of curve which human task performance shows. Matching real-world performance data will make the game’s resolution mechanism more believable.

Third, the dice mechanic should be seen as a modification to character skill, which represents the effects of “luck.” This is well-served by a distribution centered about zero, which sometimes is a benefit and sometimes is a penalty.

Finally, luck should be more important in the short term than in the long term. This means that long-term tasks should have a smaller luck factor than short-term tasks. To do this, we must be able to scale our mechanic’s degree of variation.

FUDGE-like dice can be made from dice other than d6’s, to meet the needs of games with smaller grain size. For example, 12-sided dice with 6 blank sides and one side labeled each of: +1, -1, +2, -2, +3, -3 will create a smooth bell curve if used appropriately. For example: roll 3 of these dice, and roll one more die if all dice are of the same mathematical sign. Keep rolling an extra die so long as the same mathematical sign occurs. This method can be scaled to more or less variation by rolling more or fewer dice.

“Die minus die” mechanics work by rolling two dice of the same size, and subtracting one die from the other. These can be made to open-end fairly smoothly by awarding an extra die when a maximum value is rolled.

The variation can be controlled by varying the size of the dice rolled. This method produces a curve that is less bell-shaped than that of most FUDGE-like dice. This can be improved by rolling a neutral third die, which replaces the lesser of the other two dice if the neutral die’s value is greater.

I had one ex-player comment that he didn’t like my game system because “the dice don’t count for enough.” It was music to my ears.

What's up with the total misrepresentation of Lee's post? I figured it out the first time, and what he said was so evident, I didn't post. I'm a bit confused at everyone else's interpretations of it.

Fudge (and similar systems) psychologically seem to put the skill first because the average attempt with a skill will result in the same quantity as the skill itself. In other words, if you have a Good skill, and use it, on average you will have a Good result. This is opposed to a game where you have a skill of +5 and on average have a result of +10, for example.

In addition, I think Lee did talk about the non-psychological factors of games like this. Fudge, for example, has a smaller distribution scale than, say, d20, where Fortune is much more important than skill for the first 5 or so levels.

What Lee appeared to say to me - and correct me if I'm wrong, Lee - is that in a system that attempts to appear to simulate realistic situations (note the difference between appearing to simulate realism and simulating realism - they're worlds apart), having skills both appear to be primary, and possibly being actually mathematically primary, is a good thing, and something that may not have been explored fully.

I've seen quite a few attacks like "but why is realism a good thing?" That's not the argument - games can focus on realism or competition or genre-emulation or story or whatever-the-fuck. What matters is "how do we achieve the goal we've set?" I think Lee may be on the right path here.

Lee said specifically things like "pure simulationist ethic", "I'd intended the essay to really only apply to Sim games", "From a Simulationist perspective", "let us examine what those dice represent in a Simulationist game".

I never once saw any limiting of that to a subset like realism. In fact, it seemed to imply that all Sim should be realistic. Which I disagree with. If your intention, Lee, was to speak to a smaller subset, then I apollogise. Consider all those remarks to just be an extended statement on my part on the variety of Sim, and having nothing to do with your point, then. I would warn you to watch your phraseology, however.

I still disagree on the psychology thing. I personally always find numbers to be more intuitive when describing anything with a magnitude than a word. I don't know how much better Good is than Fair, but I can tell you that 4 is twice as good as 2. Or give you the odds in a system. Put word in the way, and I have to translate before giving odds.

I may be strange in this, but it still seems to just be opinion. I'd like to see some justification for this statement about the psychology involved.

Mike

Lee Short wrote: What properties in a dice mechanic will improve the situation?

First, the mechanic should have a very low handling time. A mechanic which has long handling time will increase the attention given to the dice, subjectively increasing their importance in the resolution system. Low handling time will keep the game’s focus on events in the game world.

Second, the system should be a smoothly opened-end bell curve with no boundary conditions. This is the type of curve which human task performance shows. Matching real-world performance data will make the game’s resolution mechanism more believable.

Third, the dice mechanic should be seen as a modification to character skill, which represents the effects of “luck.” This is well-served by a distribution centered about zero, which sometimes is a benefit and sometimes is a penalty. The dice mechanic should also be scaled so that usually skill dominates over luck.

Finally, luck should be more important in the short term than in the long term. This means that long-term tasks should have a smaller luck factor than short-term tasks. To do this, we must be able to scale our mechanic’s degree of variation.

Two mechanics meet these criteria: FUDGE-like dice and “die minus die” mechanics.

Hello,

I shall do some more Moderating.

Mike, please try to minimize the line-by-line method of answering posts, for all the reasons you know. Once in a while is fine, but in a discussion like this one, it tends to breed like responses, and then everything goes kerflooey.

Also, one phrasing you used caught my eye ... you "warned" Lee regarding his terms. "Warning" is not something I'm going to permit from anyone but moderators, which in this forum - all of the non-publisher forums - are only Clinton and me, and it doesn't apply to terms debates anyway.

I'm pretty sure you were using "warning" in an intellectual sense only, and I appreciate your attention to the issue (I agree with the point you were making) ... but phrasing like "I think it's more correct to say" and so on is going to be more effective and less likely to be misunderstood. The potential for phrasing like "warning" to prompt a big bitch-session is way too high.

Best,
Ron

Lee, you're talking about something I myself have been spending a lot of time considering.

One of my own personal big beefs with many systems is excessive randomness. I've dealt with the subject elsewhere in detail. Anyway, as was argued there (not just by me), is that randomness is in many sim systems kept static despite more detail is known.

A better approach might be to reduce dice randomness as the givens are more well known and as the situation is less affected by randomness.

If I am a little better than Bob at playing cards, I might win over him more times than he wins over me. But the chances I have of winning a single game might be very random. On the other hand if we armwrestle it quickly becomes quite predictable who will win.

Or in other words, some situations are more predictable than others. This is almost always ignored.

Another thing is the effect of *when* to ask for die rolls. If I have to roll every 10 minutes to keep tracking or if I just make a single roll to see if I succeed or not makes a BIG difference in variation of outcome, and yet most games put in those rules arbitrarily with no thought of how they actually play out.

I had a long, somewhat different reply written yesterday afternoon -- but I resized my browser window to grab a quote, and it reloaded the page :-(.

I must admit to having a certain amount of baggage with respect to the term Simulationist, as I was one of the regulars on rec.games.frp.advocacy while these terms were debated. I think's that Ron's definitions are generally an improvement on the ones rgfa came to a consensus on.

That said, I don't believe that this criticism is limited to 'realism', as defined in Ron's GNS essay. Let's look at that definition:

The sub-set of Simulationism most fully developed during the 1980s was "realist" (a form of Situtation) and "genre-faithfulness" (System with strong and various other co-emphases). Some conventions of these approaches include identifying Fortune methods with the imaginary physics of the setting and a commitment to extensive search and handling times.

The key to Simulationist play is that imagining the designated features is prioritized over any other aspect of role-playing, most especially over any metagame concerns. The name Simulationism refers to the priority placed on resolving the Explored feature(s) in in-game, internally causal terms.

J B Bell wrote: I have to disagree about FUDGE putting primacy on skills. Maybe it is in the text, but in actual play, the dice are terrifically variable; perhaps one of the most common topics on the mailing list, if not the most common, is how to mitigate a really evil "whiff factor."

--JB

To start with -- is there some trick to editing in this little reply box? I seem to keep deleting more or less than I want to, and I'm getting pretty tired of retyping stuff. Or am I better off just copying stuff over to a text editor?

Mike Holmes wrote:
Interestingly, you say that the FUDGE method is better psychologically. Do you have any evidence for this? You admit that they are mathematically similar in some cases. So in those cases it's only psychology that gets in the way. But, other than personal bias (I could tell you that I don't feel that way, but that would just be my bias), do you have any evidence to back this up? I don't believe it's true, personally. If they are mathematically the same, then they seem exactly the same to me.

Mike Holmes wrote: I think that FUDGE has had some considerable impact. Considering its distribution scheme, the amount of talk it generates, and the relative lateness of its arrival, I think it's generated quite a lot of buzz. You aren't the first person to laud its design merits here. Do a search on the term Transparency to get an idea of how often this comes up.

In addition, I think that the Sim crowd is exactly the crowd that looks at FUDGE most often (it being highly Simulationist). Who else is looking at it more closely?

To begin, let us examine what those dice represent in a Simulationist game. For the game to qualify as Simulationist, the dice must represent something inside the game world. Otherwise they should not be used at all.

Mike Holmes wrote:

Commonly, what the dice represent in the game world are the numerous micro-scaled factors that effect task performance. Informally termed ?luck?, these factors are too small to have an effect individually, yet have a macro scale effect in toto.

Yes, commonly. But this does not have to be the case. They can represent meta-game concerns. Yes, even in a Sim game. Or other things. This should not be an assumption.

Mike Holmes wrote:

I had one ex-player comment that he didn?t like my game system because ?the dice don?t count for enough.? It was music to my ears.

Odd statement. Isn't player satisfaction what we're looking for here?

Lee Short wrote:
I guess my basic point here is that any game that includes rules for skill performance is, in Clinton's words, "attempting to appear to simulate realistic situations" to some degree or another. Why not do a good job at it?

Hi Lee,

Interesting thread on an interesting topic.

I'm inclined to agree with your core idea, that there are psychological factors that can make a system seem more "dice primary" or "skill primary." However, I believe those factors are more varied than you've hypothesized. In particular, I'll show you a system that appears to have the characteristics you regard as definitional for dice-primary-ness (one evaluates the situation, determines a probability of success, and then rolls against that probability), and yet has all the mathematical properties you associate with skill-primary-ness (it's centered on a 50% chance, is open-ended, has a smooth bell-like curve, and is easy to adjust for the appropriate degree of performance variance).

First, though, the psychological factors. One of the most basic, which you've implied but not stated outright in your analysis, is the order in which actions are performed. Consider two different resolution procedures:

A. Add 6 to your skill level, then subtract the difficulty, to get your target number. Roll the target number or higher on a d10 to succeed.

B. Roll a d10. Add your skill, and subtract the difficulty. If the result is 6 or greater, you succeed.

I submit that procedure B is more skill-primary and less dice-primary than procedure A. It's natural to pay the most attention to the most recently performed action. In A the die roll is the climax of the whole process. If the outcome is not successful, the player will tend to attribute that to the roll not being high enough rather than to the situation factors that caused the target number to be high. In B, the player will tend to see a failure as the skill (relative to the difficulty) not being high enough rather than the roll being too low to overcome. This is a subtle effect, but we're talking about subtle effects here. (Perhaps this is too obvious to mention, but many players like the drama of a climactic deciding dice roll at the end after the TN is determined.)

The relative wording of A and B is also an example of another type of factor. Notice the second sentence in A. What do you do to succeed? You roll. Thus only the act of rolling is directly associated with succeeding, with all those additional instructions about how to arrive at the TN being clearly secondary. In B, you succeed by meeting a condition. That condition comes about based on, let's see, the difficulty, the skill, and oh yeah, the die roll. A very different feeling.

Another psychological factor is the dice-handling time (which is some portion of the overall handling time that you noted as a factor). In particular, time spent reading and interpreting the results of the roll itself. The extra die used to smooth the curve in a die minus die mechanism could be counterproductive in that regard.

Finally, I agree with you that associating the roll with what it represents in-game does make a difference (a subtle one, as all of these are). That's where the die + skill vs. die + difficulty mechanism (mathematically equivalent to the die minus die mechanism) shines. The die added to skill can represent the performance uncertainty, while the die added to difficulty can represent the amount of resistance the world puts up -- the performance of an opponent, or that portion of the task's difficulty that can't be known "until you try it." (Note that when interpreted that way, neither single die has the bell curve it would need to realistically represent human performance variation. Oh well. Also note that the third die mechanism is hard to fit within this interpretation, and kind of pulls the whole thing back to an abstract number-juggling level.)

By contrast, I don't see the Fudge dice as particulary good (or bad) in this regard. Dice pools in some simulationist systems (especially opposed dice pool vs. dice pool rolls) can have far clearer in-game meanings. Often each die in the pool represents a specific factor in the situation being resolved. If you wanted to (and some new indie systems discussed here have begun doing things like this) you could keep track of which dice represent which factors, and use that to help narrate the details of the outcome.

[Note: Those who have already seen all they want to of Symmetry can skip the rest.]

The system I mentioned earlier that seems to cross your categories is one I've used in many of my homebrews. It's based on an integer score derived from the situation (e.g. skill minus difficulty), where a score of zero (skill = difficulty) represents a success probability of 50%. The chance of failure decreases exponentially for positive scores, while the chance of success decreases exponentially for negative scores.

p (probability of success) as a function of m (score):

p = 1 - ((1 / (a ^ (m/b))) / 2) when m >= 0
p = (1 / (a ^ (-m/b))) / 2 when m < 0

The parameters a and b determine the rate of exponential decay as a function of the score (effectively, the performance variance). The probability of success/failure decreases by a factor of exactly a for each decrease/increase of b points in the score. (One point added to/decremented from the score decreases the chance of failure/success by a factor of the b-th root of a.) Most often I use a = 2 and b = 4.

The advantage of using exponential decay functions is that the influence of situational modifiers becomes consistent and easy to understand and handle, a property that most systems don't have. (Dice pool systems do have this property as long as the the pool isn't too small and/or the modifiers are in the character's favor.) So not only is it easy to know what difficulty will give a character a 50% chance -- whatever difficulty results in a score of zero (usually a difficulty equal to the character's skill score) -- it is also easy to assign modifiers for individual situational factors, which remain correct and well-behaved when combined. A negative modifier of b points causes the chance of succcess to decrease by a factor of a (when the score is negative), and a positive modifier of b points causes the chance of failure to decrease by a factor of a (when the score is positive). Thus, if a = 2 and b = 4, a modifier of -4 points makes the task "twice as hard" as it otherwise would be, to as consistent an extent possible, regardless of what the score is initially or what other modifiers also apply. A -1 modifier is exactly one fourth as powerful. And there are absolutely no edge effects whatsoever, since there are no edges anywhere.

There are two different procedures I've used to implement this mechanism. My original method many years ago was to use the formulas to create a (one-dimensional) table of probabilities, and roll percentile dice against the probability indicated in the table for a given score. With this method, it would be relatively easy to make the table two-dimensional with varying values of a or b to represent situations of different performance variance, although I never found it necessary to do so. The alternative method I use now is to convert the score directly into a dice pool roll that yields the same (or approximately the same) probability of success as the table. The pool contains one 50-50 die, and a variable number of modifier dice depending on the score. The modifier dice in the roll directly represent the modifying factors (actually, only those modifying factors not offset by opposing modifying factors). It would be very awkward to have different dice to roll for different variances, but it's so easy to re-scale the scores instead as needed that this shouldn't be necessary anyway.

(Lots more details and rationale for this mechanism on the Symmetry thread.)

It would be interesting to see where you'd place this on the dice primary to skill primary continuum (actually, I prefer to think of it as situation primary instead of skill primary), and why. (My main concern in its design was the handling of cumulative modifiers, not the psychological nuances.) And is there any significant psychological difference between the table method and the dice pool method, even though they have the same knowledge going in (the score), the same results coming out, and most of the same information in between? In the table method the exact probability is known; in the dice pool method the approximate probability is fairly easy to deduce from the number and type of modifier dice in the roll.

- Walt

Lee Short wrote: For example, 12-sided dice with 6 blank sides and one side labeled each of: +1, -1, +2, -2, +3, -3 will create a smooth bell curve if used appropriately.

wfreitag wrote: Hi Lee,

Interesting thread on an interesting topic.

I'm inclined to agree with your core idea, that there are psychological factors that can make a system seem more "dice primary" or "skill primary." However, I believe those factors are more varied than you've hypothesized. In particular, I'll show you a system that appears to have the characteristics you regard as definitional for dice-primary-ness (one evaluates the situation, determines a probability of success, and then rolls against that probability), and yet has all the mathematical properties you associate with skill-primary-ness (it's centered on a 50% chance, is open-ended, has a smooth bell-like curve, and is easy to adjust for the appropriate degree of performance variance).

First, though, the psychological factors. One of the most basic, which you've implied but not stated outright in your analysis, is the order in which actions are performed. Consider two different resolution procedures:

A. Add 6 to your skill level, then subtract the difficulty, to get your target number. Roll the target number or higher on a d10 to succeed.

B. Roll a d10. Add your skill, and subtract the difficulty. If the result is 6 or greater, you succeed.

I submit that procedure B is more skill-primary and less dice-primary than procedure A. [snip]

[snip]

Another psychological factor is the dice-handling time (which is some portion of the overall handling time that you noted as a factor). In particular, time spent reading and interpreting the results of the roll itself. The extra die used to smooth the curve in a die minus die mechanism could be counterproductive in that regard.

wfreitag wrote:
Finally, I agree with you that associating the roll with what it represents in-game does make a difference (a subtle one, as all of these are). That's where the die + skill vs. die + difficulty mechanism (mathematically equivalent to the die minus die mechanism) shines. The die added to skill can represent the performance uncertainty, while the die added to difficulty can represent the amount of resistance the world puts up -- the performance of an opponent, or that portion of the task's difficulty that can't be known "until you try it." (Note that when interpreted that way, neither single die has the bell curve it would need to realistically represent human performance variation. Oh well. Also note that the third die mechanism is hard to fit within this interpretation, and kind of pulls the whole thing back to an abstract number-juggling level.)

By contrast, I don't see the Fudge dice as particulary good (or bad) in this regard.

wfreitag wrote:
The system I mentioned earlier that seems to cross your categories is one I've used in many of my homebrews. It's based on an integer score derived from the situation (e.g. skill minus difficulty), where a score of zero (skill = difficulty) represents a success probability of 50%. The chance of failure decreases exponentially for positive scores, while the chance of success decreases exponentially for negative scores.

p (probability of success) as a function of m (score):

p = 1 - ((1 / (a ^ (m/b))) / 2) when m >= 0
p = (1 / (a ^ (-m/b))) / 2 when m < 0

The parameters a and b determine the rate of exponential decay as a function of the score (effectively, the performance variance). The probability of success/failure decreases by a factor of exactly a for each decrease/increase of b points in the score. (One point added to/decremented from the score decreases the chance of failure/success by a factor of the b-th root of a.) Most often I use a = 2 and b = 4.

The advantage of using exponential decay functions is that the influence of situational modifiers becomes consistent and easy to understand and handle, a property that most systems don't have.

wfreitag wrote:
(Dice pool systems do have this property as long as the the pool isn't too small and/or the modifiers are in the character's favor.)

wfreitag wrote:
So not only is it easy to know what difficulty will give a character a 50% chance -- whatever difficulty results in a score of zero (usually a difficulty equal to the character's skill score) -- it is also easy to assign modifiers for individual situational factors, which remain correct and well-behaved when combined. [snip]

[snip]

It would be interesting to see where you'd place this on the dice primary to skill primary continuum (actually, I prefer to think of it as situation primary instead of skill primary), and why. (My main concern in its design was the handling of cumulative modifiers, not the psychological nuances.) And is there any significant psychological difference between the table method and the dice pool method, even though they have the same knowledge going in (the score), the same results coming out, and most of the same information in between? In the table method the exact probability is known; in the dice pool method the approximate probability is fairly easy to deduce from the number and type of modifier dice in the roll.

- Walt

Hey Lee, I'm going to ramble on a bit, and it's possible I've totally failed to get the point of your post. If I have, I appologize in advance, and please correct me. :)

First off, I don't agree with you that it's limited to simulationist games. IMO, the concept is important regardless of your preferred play style.

A related topic that I've discussed many times is whether or not to use a universal or unique rating system. That is, whether or not each character is rated with a common set of categories (D&D attributes), or a set of unique traits (Pool traits), or some combination thereof (most attribute + skill systems). D&D characters often appear to be very similar, even though their in-game abilities may be quite different, while each Pool character is extremely unique and flavor-filled. (In case you haven't noticed, I prefere the non-categorical method. ;)

I think your idea is almost paralell with this idea. A die mechanic can have appearance in exactly the same way character representation can. I almost think that this topic would fall into the category of "color," because that's mostly what it deals with... flavoring the game.

Fist off Lee I completely understand where you are coming from. Part of the reason for this is because I am not a math wiz. Another reason is because I am very open minded to this new way of doing things.

Try to follow my analogy without nitpicking I’m not having a very good morning.

The search for the PERFECT RPG rules is like the search for the grand unified theory. A straight chance system (roll one die every face is an equal chance) was a very early understanding of how chance worked. It’s like Newtonian physics, it works for most problems, and where it dose tend to fall apart additional rules can be tacked on. Then came along the bell curve systems (personal favorite is FUDGE by the way), this was like Einstein coming up with E=mc^2. On the surface it seems less intuitive, that and its new and unproven. It took a long time for science to accept this new theory mostly because that meant unlearning all the tricks they were using for Newtonian theory. In a way it also set science back several years as everything had to be reevaluated. I think that the straight chance systems have been tricked out so to speak, there is not much room for growth. The FUDGE-like systems are new and are forcing a rethinking of how things are done and why on a more basic level than most of us are accustomed to thinking about. I am ambitiously rewriting the basic FUDGE rules for a Sci-Fi RPG. I hope to show with it that FUDGE-like systems are more optimal for realistic settings (though with lots of gamer elements thrown in).

Forlarren wrote: The search for the PERFECT RPG rules is like the search for the grand unified theory.

Paganini wrote: Hey Lee, I'm going to ramble on a bit, and it's possible I've totally failed to get the point of your post. If I have, I apologize in advance, and please correct me. :)

First off, I don't agree with you that it's limited to simulationist games. IMO, the concept is important regardless of your preferred play style.

Paganini wrote:
A related topic that I've discussed many times is whether or not to use a universal or unique rating system. That is, whether or not each character is rated with a common set of categories (D&D attributes), or a set of unique traits (Pool traits), or some combination thereof (most attribute + skill systems). D&D characters often appear to be very similar, even though their in-game abilities may be quite different, while each Pool character is extremely unique and flavor-filled. (In case you haven't noticed, I prefere the non-categorical method. ;)

I think your idea is almost paralell with this idea. A die mechanic can have appearance in exactly the same way character representation can. I almost think that this topic would fall into the category of "color," because that's mostly what it deals with... flavoring the game.

Lee,

With FUDGE or a similar system it isn't easier to produce reasonable difficulty numbers. With the standard system you can get the same information by simply adding the average dice value to the skill. The average expected value is skill plus die average, if the die average is zero, ie FUDGE, well it doesn't really matter.

Further, it is far harder to calculate the probability with system using a bell curve during play, so you may not know the probability of a player succeeding at a difficulty two points above his current level, whereas with a d6, or any other single die, is very easy to find. If you want a system that models real performance, then a bell distributed system is wise, but appropriate difficulty numbers are always harder to find, never easier.

The psychology aspect is interesting, but isn't it based more on std dev of skill vs std dev of dice, rather than the order they are added together?

Jeremy