In games it’s not unusual to have to compare two values and to modify these based on bonuses or penalties that players have accrued throughout their actions. There are good reasons for this: It allows a designer to make a broad range of player actions meaningful, while still paring the result down to a single important outcome – whether a battle is won or lost, who gets the item, does this hero live or die. These combine creating drama with making previous meaningful decisions have a coherent reward.

When implementing modifiers in a situation like this there is an important design decision to make: How fine grained should the modifiers be.

Because of how numbers work, there are an infinite number of modifiers that can be applied to any test. Even if players have a level of 0 or 1 and will never be outside of the 0-1 range a bonus could be +0.5 or +0.05 or +0.005 … you get the idea.

You should see the strengths and weaknesses of a fine grained system right away. In a system that is too fine grained the modifiers add unnecessary complexity. It’s slower to do “10 + 5.65 + 3.21 + 4.5” than “10 + 6 + 3 + 5” You’d also have more trouble tracking the game state, requiring a better memory or fiddler counters.

On the other hand a system that paints in broad strokes is unable to encapsulate things that should have a different level of impact. At its most extreme you might have a system that only allows a +1 modifier, no other value is possible. Imagine you have spent the whole game working on your city, collecting resources and trading them to develop new technologies and defences. Your laser walled sci-fi super-city gets a +1 to defence. Meanwhile your opponent decided that he’d give one of his be besieging pikemen a shiny rock. that gives him +1 attack. The battle is even despite your greater investment, both mechanically and thematically, in winning this sort of conflict.

As a designer it is usually very easy to detect when you do not have a high enough degree of precision. Playtesters are usually very quick to point out when something is unsatisfying, either because it gave them too little or gave their opponent too much.

It is harder to know where a lower degree would be useful. The only real way to find out is to trial a system with less nuance and see how it goes.

I tried this earlier today with Genesis. The current build of the game allows champions to get modifiers to their power, ranging from about -6 to +6 (Though some are in the form of “1 per character that died” and can theoretically hit higher levels).

Players are expressing difficulty in keeping track of what bonuses and penalties apply to a champion. According to their feedback forms some have proxied additional components to keep track of transient bonuses and penalties. There are suggestions that the game might embrace this, but I wonder if we could go one better and make it easy to remember, or at least easy to track with the components available.

My test is this:
Any modifier providing +1 or +2 now provides “bonus”
Any modifier providing +3 or higher now provides “bonus bonus”
Similarly negative modifiers provide “penalty” or “penalty penalty”
When a character gets a bonus they’re rotated 45 degrees right (unless already at 90 degrees)
When a character gets a penalty they’re rotated 45 degrees left (unless already at 90 degrees)
At any given moment a card can be in one of five states: Upright, one bonus, one penalty, two bonuses, two penalties.
These are assigned values of -5, -2, 0, +2 and +5
The question is “Does playing the game this way, with all modifiers reduced to bonuses or penalties on a five point scale, produce different results to playing under the current rules?”

Obviously I started playing with myself at once. After 3 games of 9 turns each the bonus/penalty system produced a different result on only 1 turn. The totals were very often slightly different, but in terms of game outcomes this often changed the margin of victory without changing the victor. It was rare for a character to miss out on a bonus or penalty because they’d already had two and when it occurred it tended not to change the outcome. Ultimately a hard to track 13 point scale is providing almost no additional nuance over an easier to track 5 point scale.

The next test is to consider whether it would be sufficient to just have a 3 point scale in which each champion either has a bonus, a penalty or neither (or both). I suspect here many more outcomes will change as hard to acquire bonuses that are presently coded as +4ish (or “bonus bonus”) in the retest will be weakened to match easy to acquire bonuses – but it is best to carry out the test anyway rather than assume.

After that the next step will be finding a sensible way to codify and explain the alternative rule. I think I’ve made a bit of a meal of it in this post, there’s probably a much simpler way to put it.

I hope that gives a good idea of why it’s meaningful to talk about how much precision modifiers have and shows a useful technique for determining if you should change yours in practice. Let me know in the comments if you think there are any games that are good examples of getting precision very precisely right or hilariously wrong.