Implicit Consitency

Date authored: Feb. 2nd, 2007

Note: This essay draws its examples from the DSA 4.1 ruleset, but addresses a general point.

We happen to play a lot of DSA lately since I’m leading a campaign in Aventurien, DSA’s world. For those who don’t know the abbreviation, DSA stands for “Das Schwarze Auge” (en. “The Black Eye”); it’s a german RPG. It is fun, and Aventurien is a wonderful world. However, the system has a consistency problem. It’s not the layout, which is fine, or the art and drawings, which are mostly black and white but nevertheless nice, and it isn’t that a core rule book formulates a rule that is contradicted by another. No, DSA has a problem with what I’d like to call Implicit Consistency.

Implicit Consistency happens to be when one can reason some part of the rules from the rest by taking an educated guess. When a rule system is implicitly consitent, an experienced game master can grasp the inner workings of the system quickly and derive most, if not all, of the relevant rules directly, needing to refer to the rule book only for details or tabulated data.

Take, for an example, penalties applied to actions. In DSA, a fighter can aquire several feats. One among them is the power attack. With it, the player can voluntary take a penalty to his liking on the next attack, and if he succeeds, this penalty will be applied to the damage caused by his weapon. The DSA-style power attack has a mandatory penalty of +4 which isn’t added to the final damage. (With DSA, the lower the numbers, the better, so a penalty gets added to the final dice result.) For example, if you want to cause 5 additional points damage, you have to take a penalty of 9 = 5+4.

Other feats work in the same way; you take a +4 penalty and gain something extra for it. They are, basically, special maneuvers you can exercise during combat. For some of them advanced version exist; the power attack is followed by the hammer blow, beeing a more deadly variant where the final damage is tripled. The player can, as with the power attack, take a voluntary penalty, and also the hammer blow features a base penalty. Here, it is +8.

Judging from the feats one gets the following idea: Many special maneuvers come with a +4 penalty, more advanced action even with +8.

However, looking at the distance classes, this assumption isn’t true any more. DSA employs distance classes to make weapons of different length useful. Somebody carrying a pike is able to deliver a possibly deadly blow earlier than the attacker that merely has a knife, but if the knife-bearer is finally able to underrun the pike’s length, the defender will be in dire trouble. A battle always starts in the outermost distance class possible. In our example, the pikeman is the one to fight in the ideal distance class. The fighter with the knife has to make an attack to get nearer. The knife-bearer’s player has to take a penalty, of course, since it’s a special maneuver. One would think that getting into the next nearest distance class is an attack +4. But it isn’t; instead, the attacker takes a +6 penalty.

Different scene: Skill checks. Of course, DSA features advices on how a game master could apply penalties to actions that are harder to accomplish than normal. The penalty table goes like this: 0/+3/+7/+12/+18/+25, so the penalties become worse by 3, 4, 5, 6, and 7 points. That will be hard to guess if the game master doesn’t know it from memory!

DSA is not, of course, by far the only game system where designers thought that diversity in constants would be enriching to the system. Anima: Beyond Fantasy also has so many different aspects in its rules that it is hard to

Why is it important? Because implicit consistency make a rule system easier to learn and, therefore, possibly more enjoyable: Breaking the flow of the current game session is something a GM wants to avoid. No one doesn’t want to spend minutes over minutes studying one of the several core rule books searching for whatever penalty applies right now during the session. While playing, the whole group usually has better things to do than consulting the rules, like fighting. It destroys the precious atmosphere.

“Why then,” I hear you ask, “doesn’t the GM just apply the penalty he deems appropriate?” It’s a valid suggestion, and I’d normally do it that way. The problem is with the beginnings: Newbies do not yet have the sense for the particular system’s finer mechanics. How does a newbie know whether +4 is apropriate? It could be too much, thus ruining it all, or it could be too little, thereby making things to easy, and again spoiling the fun. We’ve all started as newbies ─ we all depended on those pieces of information like “how much penalty should I apply to this action that isn’t hard, but not common?” And, besides that, for other things, this isn’t possible: The hammer blow will always come with +8.

This problem arises in many ways, not only with penalties to dice rolls. Whenever it comes to numbers, neither game masters nor players usually want to cram tables just to make the game play fluent. Taking an ‘educated guess’ should be the appropriate solution to all those problems ─ and players and game masters alike should usually be right with their guess.

A solution to this could be to introduce ‘difficulty classes’ that come with a static penalty. Something is ordinary: ±0. Everything else means a stacking +4 penalty. Difficult: +4. Hard: +4+4 = +8. Even harder: +4+4+4, +4+4+4+4, and so on. I guess you get the idea.

Of course, this is very specific to checks and penalties. Generally spoken, if you, dear reader, were about to create a RPG rules system, you would make sure you have a pool of decent numbers. Whenever you brood over a rule and catch yourself out on thinking of a number: Stop it. Concepts must be simple. Some few but basic meta-concepts must exist that span all rules. Having common numbers is one of them.