Veil's End

Where I last left off on mechanics, I was going over some of the basic dice systems that a commonly used in RPGs. In this post I’ll start to go over my thought process on designing my dice system. My requirements are:

1. Fast
2. Varying levels of critical success.
3. Even progression for upgrades.
4. High variance of results at low levels of skill, and low levels of variance at high levels of skill.

For the first requirement, fixed dice systems are usually fastest, followed by progression dice systems, with dice pool systems usually trending on the slower side of the equation. The reason why fixed dice systems are generally fastest for resolving checks is because you’re pretty much always rolling the same single die for each check, or at most the same couple of dice for each check. For example, if you’re playing a game where you roll a single 20 sided die to see if you hit
the monster with an axe, you’re always going to be rolling a single 20 sided die to see if you hit, no matter what. Compare this to dice pool systems, where you’re rolling numerous dice for each check, and the better your ability, the more dice you’re going to be rolling. Progression dice systems generally have you roll a single die at lower levels of ability, but multiple dice at higher levels of ability. However, most progression dice systems won’t have you rolling nearly as many dice as a dice pool system. Another mechanic that affects speed are whether or not you’re comparing the results of your roll against a static target number, or having all parties roll dice and comparing the results. Re-rolling dice will also slow things down. Both of these mechanics are a bit slower for fixed dice systems and often times a LOT slower in dice pool systems. Just imagine an attacker and defender rolling about 10 dice each, with re-roll mechanics, and then comparing the results to see who hit whom. Ugh. And lastly, math slows things down. Bonuses and penalties, either applied before or after a dice roll, will take up time. This affects fixed dice systems the least, but can really be a problem in both progression dice systems and dice pool systems. With those two systems you can have both modifiers to what kind/how many dice are used, AND modifiers added or subtracted from each die roll result. So just based on speed, I’d lean towards a fixed die system, against a dice pool system, and “possibly” on a progression dice system.

I think my second requirement is doable with any of the three dice mechanics I’m looking at, but easier with progression and pool systems. With those two systems, I can just have any die that rolls the highest number possible on that die rolled again and added to the total. For example, if I roll a six sided die and happen to roll a 6, I’d then roll another six sided die to add to the total. So if I rolled a 6 and the second die rolled a 4, my total would be 10. But if I rolled a 6, followed by another 6, I’d roll a 3rd die to add. So on and so forth. This gives me critical successes that can be just a bit better, or if you’re super lucky, up to a LOT better. This is trickier with fixed die systems that have you roll a single die that has a wide spread of possible results. Critical successes happen much less frequently, but when they do happen they are crazy good. For example, if I roll a single twenty sided die, I’d only get to add another die if I rolled a 20, but if I do roll a 20 and add another d20, my result could be crazy high. This re-roll and add mechanic is often referred to as “exploding dice”. Based just on this requirement, I’d lean towards either a pool or progression system, and away from a fixed die system.

My third requirement is pretty much totally doable with every dice system except dice pool systems with exploding dice testing against static target numbers. This is because you’re always rolling the same type of die in a pool system, and if your target number is N+1, where N= the number of sides on your die, then any upgrade you get that puts your target number to 1 + any number divisible by N is worthless. For example, if we use six sided dice for our pool, if the target number to hit me is 6, then upgrading my skills/gear/etc to make the target number 7 is wasted effort. This is because any time you roll a 6, you roll another die to add to the total, so if you roll a 6 you’re definitely going to get a total result of at least 7. This actually comes up as a problem in multiple very popular RPGs.

This last requirement is really only easy to achieve with a progression die system. At low levels of ability in a progression die system, you roll a single die (d4, d6, d8, d10, etc etc). At higher levels of ability you roll multiple dice and add the results together (2d6, d6+d8, d6+d10, etc etc). When you roll a single die, you have an even distribution of results (high variability), and when you roll multiple dice and add the results, you have a bell curve for the distribution of results. The higher level your ability, the more dice you’ll be rolling, and the higher the peak in the bell curve for your results probability. Your roll results become more predictable. This is exactly what I’m looking for.

Given all of this, I think I’ll be using a progression die system. I’ll use re-roll mechanics for the varying critical successes. To keep a fast pace, I’ll want to have most checks made against static target numbers. However, I think I’ll still have some opposed rolls for very dramatic and seldom made checks. For example, I’ll try to have most combat tests made against a static number, as that what is likely to generate the majority of an gaming evening’s dice rolls. But I’ll have things like sneaking and social skills opposed. They’re pretty dramatic events, and they don’t usually occur as often as combat tests.

Now that I’ve got a general outline for this project, I’m going to start working on the core rules of the game. I’m dividing this up into several categories; Dice Mechanics, how to determine success/failure for actions (how combat works for example), and how to create and measure progress of characters (xp, leveling, learning new skills, etc). The first step I’ll take is to settle on a dice mechanic.

I want to be very deliberate about how I design the mechanics for this game, so instead of just picking whatever dice system I’m most familiar with, I’m going to start out with a set of objectives that I want my dice system to achieve, and then design the dice system to meet those objectives.

1. I want a system that is “fast”. The less time spent figuring out what dice you need to roll, and/or what the die roll result actually is after all modifiers, the better. However, this needs to be balanced out by not having a system that is too simplistic to allow for variables in a check.
2. I want a mechanic that allows for various levels of critical success, ranging from better than average,  up to (albeit extremely rare) fantastic results. The reason for this is that even having the “chance” at a phenomenal result can sometimes drastically change the player’s behavior.  If you know that you can’t succeed, you won’t even try – however, if you know there is a (snowball’s) chance (in Hell), you “may” try, and you might even succeed. Those epic successes against all odds are what players will talk about long after the game session has finished for the night. I know that I still remember my best friend in middle school shooting a dragon in the eye with a called shot (house rule) on a natural 20 in a D&D campaign almost twenty (damn, feeling old moment…) years ago.
3. I want skill/attribute/equipment/etc improvements to have a steady progression in the bonus they contribute. No “worthless” levels of upgrades.
4. I want the level of randomness in dice roll totals to trend from volatility at low levels of skill, towards stability at higher levels of skill. This allows high skill level attempts much greater predictability of the outcome (the veteran Warrior is generally able to hit low level thugs), while still allowing low skill level attempts the possibility of success (you can never be sure if that newbie Warrior can land a blow, but s/he definitely can sometimes).

I’ve played a lot of different RPG’s, using a lot of different systems. I’ve yet to find a “perfect” system, each one has its own pros and cons. That being said, most decent dice systems can be boiled down to one of three general categories; Fixed Dice, Dice Pools, and Progression Dice systems. And in these three systems, success or failure is generally resolved via opposed checks (attacker AND defender both roll – high roll wins) or checks against a static target number (attacker rolls and compares to defender’s target number), or a combination of both. And lastly, whether or not a die is ever re-rolled, or re-rolled and added to to total. That last mechanic is often referred to as “Exploding Dice”. I’ll go over some of the basic differences.

Fixed Dice:

Many of the really popular FRPG’s that most people are familiar with use some variant of a fixed die system. Most fixed die systems have you roll a single 20 sided die (d20), a “percentile die” (d100), or three 6 sided dice (3d6). With fixed-die systems, the amount of variability in any given die roll is static. That is to say, if you’re playing D&D, you’re always going to be rolling a d20 for your attack, no matter what level you are. The major difference between rolling a single die (d20) versus rolling a set of dice (3d6) is that a single die gives you a flat distribution of die roll results, whereas rolling a pool of dice gives you more of a bell curve for results. So, if you’re rolling a d20, the odds of rolling any of the 20 possible numbers is 1:20, but if you’re rolling 3d6, you’re much more likely to roll a 10 or an 11 than you are to roll a 3 or an 18. Those that are familiar with the dice game Craps are already familiar with this mechanic – rolling a 7 on 2d6 is much more likely than rolling a 2 or a 12. The more dice involved in the roll, the higher the peak and smaller the spread of the bell curve. The end result is that a single die gives you a lot of volatility in your rolls, whereas rolling a pool of dice gives you more stability/predictability in your rolls. Neither system is inherently good or bad, they’re just different mechanics to keep in mind for game designers. Fixed Dice systems can be really good for fast resolution of checks, as you’re usually only rolling a single die per check, or if you’re using a system that uses multiple dice, it’s usually not that many dice, and it’s the same set of dice each time.

Dice Pools:

Dice pool systems have you roll a pool of a single type of die, most often a pool of d6′s or d10′s. The greater your ability, the more dice you roll. There are pretty big pros and cons to dice pool systems. On the plus side, it’s generally very quick and easy to figure out what you need to roll, as there tends to be very little addition or subtraction applied to rolls. You just roll more dice or less dice depending on your ability. It’s also a fairly intuitive process to assess what your odds for success or failure are. Where dice pool systems can run into trouble is when you need to scale up a lot. Then you wind up rolling an ice cream bucket full of dice. Also, opposed checks can bog things down a lot as well.

Progression Dice:

This is a less often used system. A progression dice system has you rolling a variable amount of dice based off of your relative ability. So depending on your ability, you may roll a d2, d4, d6, d8, d10, d12, 2d6, etc to determine your result. For example, if you’re a clumsy wizard you may roll a d4 to hit someone with an axe, and if you’re an experienced warrior you may roll d10 + d8 to hit. The downside to a progression dice system is that it can be cumbersome at times to determine what kind of dice you’ll be rolling for your check, especially when you have multiple modifiers to a roll that change from round to round. Similar to dice pool systems, progression dice systems can get bogged down with adding the totals of numerous dice for each action, although it’s less of an issue in progression dice systems due to usually fewer dice being rolled per check compared to dice pool systems. On the plus side, you can really play around with probabilities with this kind of system. By having a mechanic that allows you to roll a single die at times, and multiple dice at other times, you can go back and forth from static variability to bell curve results.

Since this post has become rather long, I’ll follow up with what system I’ll use in my next post.

The first step I want to take in designing this game is to divide this process in to manageable chunks. As I see it, there are two general components to a good FRPG; the mechanics and the story. Each of these two categories branches off into numerous sub-categories, and those in turn into further sub-categories. On the mechanics side of the equation I’ll be dividing this process into the following categories; Core Rules, Races, Classes, and Equipment. I’m sub-dividing the story part of the game into Geography, History, and Race info. Sub-categories will include the political structure of each nation, the economy, culture, etc etc. I’m certain to come up with some other categories that I haven’t thought of later on. There will of course be a lot of cross over between these various categories, and I expect to revisit content in one category after working on another. Because I want the game’s mechanics “make sense” in context of the game’s story, I expect to revisit mechanics content after working on the storyline, and vice versa.