The purpose of rules

24 November, 2007 at 12:00 pm (game design, rpg theory) (, , , , )

I have dabbled in freeform. It works. This begs the question; why use rules at all?

There have, naturally, been several good answers to the question. One famous comes from the Forge and is called Lumpley principle: “System (including but not limited to ‘the rules‘) is defined as the means by which the group agrees to imagined events during play.” In essence: System, including the rules, tells who can say what and when (“what” regarding the fiction). So, what are the implications? First, all games with one GM and number of players who only decide things about the behaviour of their characters are fundamentally the same. Second, there are alternatives to that model. Third, there is always a system; rules just make it explicit.

Another, more recently surfaced, theory says that rules share spotlight (originally from Ben Robbins, further elaborated by Fang Langford here, here and here). The implications include that rules which create separate subgames (hacking in Cyberpunk) not accessible to all players are bad. In turn-based environment, such as many combat systems, rules that give extra actions should be considered carefully. Critical hits and fumbles are actually meaningful rules; they give random bursts of spotlight to players. The purpose of rules is to regulate spotlight away from those who would have it in freeform gaming.

Rules also create shared expectations with regards to the fiction and player behaviour generally, which is probably more important. The Mountain Witch (Vuoren velho in Finnish) has rules for betrayal and every player knows that every other player has a dark secret. This creates the atmosphere where betrayal is assumed to happen, at some point, and hence reduces the potential for damage that may happen with unexpected interparty conflict (see also: this RPGsite thread). Game art and such also contribute in similar manner. Under this point of view rules make the gameplay smoother; less need for negotiation, fewer mistakes that need fixing.

“The rules are the physics of the game world.” is often heard. I am going to extend it a bit: Rules define setting. The effect is not necessarily straightforward, but it is there. D&D dwarves are harder to hit by giants. There might be several reasons for this, or none at all, but it will be reflected in the setting somehow. What does this imply? Well, first, the more rules, the more defined the setting will be. This may be a perk or a flaw. Second; setting andrules interact. Choosing one will or should affect the other. Third, if you want a setting that does make sense internally, take a good look at the rules and how to translate them into in-game (diegetic) information.

Rules create tactical and strategic sub-games. Some are very explicit about this, some far less so, but at least the combat or generic conflict resolution systems tend to be minigames. Implications: Make them meaningful and fun, given that they are there.

In summary, there are several ways of looking at the purpose of rules. When selecting a ruleset, or designing one, it is useful to look at it from several perspectives.



  1. snakefing said,

    “Rules define setting,” seems a little strong to me – more like rules constrain, or partially define setting. I’m sure that’s what you meant, just a terminology quibble.

    This is really the aspect I’m most interested in. Given a genre (really, a broad category of possible settings), and a specific setting that I am designing, how might I tweak the rules to better reflect the constraints and concepts of my setting? From the point of view of a setting designer or GM, this is fairly important because I will usually want to choose an existing game engine (framework of rules) that players will be familiar with. But such engines are usually either too generic (don’t reflect the setting constraints enough) or too specific (don’t accurately reflect the constraints of my particular setting). Either way, I’ll need to tweak the rules – by adding or modifying.

    A really good game engine would probably be built with this in mind. Perhaps by making it easier for a GM to define cultures, or character classes; to implement variant systems; to ban or allow setting elements; and the like.

    I’m not sure this would be possible, of course. Any rule system tends to create its own reality; for example, by making certain character choices or strategies more effective than others. If a GM starts modifying a given game engine or rule set, there will likely be unintended consequences along these lines – modifying the reality of the setting in ways the GM did not intend.

    – snake

  2. Tommi said,

    Indeed, rules don’t completely define a setting (I don’t think a finite set of rules is even capable of that). They do, partially, ignoring few very trivial edge cases.

    Design-wise, one simple way is to make a generic ruleset that lets players decide and name their traits, as long as they remain sensible. Drawback: The rules don’t evoke the setting but leave all the trouble on the participants’ shoulders.
    You are familiar with d20, so something like Perfect 20 might be a good base to start from. It is fairly functional, IIRC.

    Tweaking something that already exists should start with a clear mission statement, consisting of two parts: 1. A well-defined setting. I assume this is not a problem. 2. The sort of gaming you want the system to be good at. GNS is one way of slicing the pie, but anything is better than nothing. To be more specific: What are playable things like? Specific species, race, culture, profession, geographical location, whatever is sentient, … What will the chars do? Adventure, political backstabbery, exploration, personal issues, war, …

    Those two somewhat determined, what kind of system will it be? I am here assuming that it has something to the effect of skills, classes, magic system, combat rules, races, perks, etc.
    See which of those fit the purpose of the ruleset. Use them as is or sprinkle with setting flavour if desired. For stuff that doesn’t fit, either remove it or change it until it fits. This should leave pretty big holes in the rules. D&D without magic items is not very balanced, for example. Now figure out a way to fill those holes with setting-appropriate material.

    That’s the process I would use. Worth a post if I come up with something useful on the subject.

    Oh, yeah, I almost forgot: Playtest. Run the creation by rules-monkeys of random internet forums and your group.

  3. Xcalaber said,

    if you want a system that has no setting what so ever then you should move the the hero system. It has rules that can make just about any character you can think of without placing a setting on it.

  4. Tommi said,

    Thanks for the comment, but I must disagree. Hero is an rpg of the “rules are the physics of the setting”-school, which means that it has built-in assumptions about, say, the deadliness of weapons, which narrows down the number of potential genres, and, hence, settings that it works well with.

  5. Good rules help to improvise « Cogito, ergo ludo. said,

    […] rpg design) (game mastering, rpg design, rpgs) When writing my previous post, I realised one important component of good rules: They actively help me in improvising content by taking the burden of decision-making away from the […]

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