Friday, April 23, 2010

Rules 2: Under/Over Specification

As we see from the previous post, induction leads to elegance. However, games often require special cases beyond a simple set of base rules. This can provide a certain amount of texture or theme.

State the general rules first. Then enumerate the exceptions using an amount of detail so as not to imply anything more or less than intended.

A player may choose one the following actions: A, B, or C. A player may never take action B followed by action A.

Huh? What is the meaning of the second sentence? Is it extraneous? Is it an example? Is it implying that a player may take action A followed by action B? Even though it isn't technically in conflict with the first sentence, its presence makes the reader wonder what they are missing. Exceptions imply things. At a minimum, players will make logical inferences.

Roll a die and move that many spaces. However, if you roll a 3, you must move exactly 3 spaces.

Again, huh? Does the second sentence imply that you may move other than your roll when you don't roll a 3? This is another example of a rules writer perhaps thinking they are being specific, but only confusing the reader.

Thursday, April 08, 2010

Rules 1: Induction

This is the first in a potential series of shorter posts discussing rules writing. An appropriate subtitle might be "How Not To Confuse Your Customers". Each designer, editor, publisher has their own strengths and weaknesses. Clearly a great deal of time is spent on various aspects of many rulebooks (eg detail, examples, art, images, component list, sequence of play, index, etc). However, ignoring some of the most fundamental aspects of rules is like spending all of your time and effort on the paint job of a building that is going to collapse. The best service you can do for your customers with regards to the rules is to makes them clear, concise, unambiguous, and elegant.

Today's topic is induction. In the most general sense, induction is the process of finding a pattern or general rule that describes a set of data. It can make a complex aspect of a set of rules an order of magnitude easier to understand and remember. Consider this generic example of a game:

We have a basic wargame. There are 3 different nations represented by the colors red, green, and blue. Within each nation, there are 3 different unit types A, B, and C. The rulebook lists their respective attack values as follows:
red A 5
red B 6
red C 7
green A 6
green B 7
green C 8
blue A 7
blue B 8
blue C 9
Obviously, there's a pattern here, but presented like this, would you not try to remember it like this? How long would you consult the chart before memorizing the numbers? How would you go about teaching this part of the game? Would you list all 9 elements? Would you just show the chart?

Now consider the following description of the above chart: The base attack value is 7. Red units are -1, and Blue are +1. A units are -1, and C units are +1.

Now you are able to state the attack value of every unit without the chart. The nations now have a "thematic" sense, as do the units. You could also add a new nation or unit type to the system simply by describing how it fits in (eg unit type D is +2, nation yellow is also -1).