You wouldn't think of arithmetic as a subject requiring special attention, but in fact there are a number of subtle factors that must be kept in mind while working with numbers in the Erasmotron.
We decided to set up the Erasmotron with a basic number range of 0 to 100. We chose this range because it's a clean, simple range that most people can instantly grasp in their heads. It's easy to think of somebody's greed as 47 on a scale of 0 to 100. If you're a hotshot with math, you know that we could just as easily have used something like 4.739 x 10**(-17), but then, there are damn few people who are hotshots with math AND hotshots with stories, and we'd prefer to reach the hotshots with stories, so we keep the math as simple as we can.
There are two killer problems that make life miserable for programmers and storybuilders, and they both arise from the fact that the computer is less than perfect. Specifically, they are round-off error and overflow/underflow.
Round-off error arises from the fact that the numbers inside the computer are integers (whole numbers); they can increase or decrease by no less than one step. Thus, a character can have greed of 3, or greed of 4, but not greed of 3.5. The most common symptom of this problem is loss of tiny increments. For example suppose that you want to change somebody's affection by one-tenth of their greed. Suppose further that their greed is 9. Well, as far as the computer is concerned, one-tenth of nine is 0, because it's not big enough to be 1, so it has to be the next smaller number, which is 0. Thus, you could do this operation (changing a person's affection by one-tenth of their greed) thousands of times and never, ever change the person's affection!
Fortunately for you, we realized that this problem would be most important with the relationships, which you often tend to change by small amounts, so we used some fancy programming to give you an extra two digits of resolution. It's kinda screwy, but basically the relationship numbers (affection, trust, submission, etc) act as if they can take steps as small as .01. For example, you can have an affection of 3.56 or 19.84. That greatly reduces this problem.
In general, round-off error will only rarely strike, but when it does, it's a real headache to figure out what's going wrong. If you refrain from having your numbers be very small (say, less than 5), you'll minimize round-off error headaches.
Overflow/underflow arises when a number gets way too big or way too negative. In general, you should try to keep most of your numbers in the range 0 to 100, but it's no crime to go higher; most of your numbers can climb all the way up to about four billion without any problem. The problem is, when you start multiplying big numbers together, they get real big real fast. For example, suppose that you had this little formula:
Inclination[Verb] <= Greed[Actor] * Integrity[Actor] * Gullibility[Actor] * Cleverness[Actor] * Timidity[Actor]
This is bad news; if you get an actor with all five factors above 90, then the final result will be too big for the computer to handle, and it will generate an overflow error and screw everything up.
There's a simple rule for avoiding problems like this, and it helps in a variety of other ways. The rule is this: each complete formula should have a "net factor count" of exactly one. A factor is any personality trait or attribute such as Greed or Cleverness. A relationship such as Affection or Trust does not count as a factor. The attribute Wealth is a special case that completely screws up this procedure. You figure the net factor count by a simple procedure:
Start with a net factor count of zero.
Examine the right side of the formula. Think of it as a sum of terms, each of which might be composed of smaller terms. Two factors added together yield a factor count of two. A factor multiplied by 5 yields a factor count of 5. Two terms multiplied together could yield a very large factor count! A term divided by 4 counts as one-quarter of a factor.
I don't want to get too mathematical here, so let me give you some samples with factor counts. Remember, a factor count of 1 is the best, and if you get a factor count much different from 1, you may generate headaches for yourself.
Formula Net Factor Count
Greed[Actor] + Integrity[Actor] 2
Greed[Actor] - Integrity[Actor] 0
Cleverness[Actor] + (Magnamity[Actor] ÷ 4) 1.25
Trust[Actor, Subject] 0
Trust[Actor, Subject] - Anger[Actor] -1
(50 * Fear[Actor]) 50
((Timidity[Actor] * Trust[Actor, Subject]) ÷ Temper[Actor] ???