A basic dice/action mechanic

[Kit]

This probably isn't terribly revolutionary (indeed I know it's not, as the basic concept is simply stolen and generalised from other games), but in the homebrew I'm fiddling with I'm using the following mechanic and was wondering what people thought of it:

Firstly, it's d100 based. The basic model is simple - you roll a d100 and add your modifiers. High is good. Often it's just to beat a DC, some time you're comparing the number against various possibilities. You can also have opposed rolls - two people roll and compare their results.

Secondly, every roll you make is of this form. There are no other types of dice involved, no other mechanics to worry about.

Thirdly, in principle every action has a roll associated to it. Breathing, talking, not dying, whatever. Most of these will have DCs which are incredibly low (e.g. on the order of -200), so in most normal circumstances you will not have to roll.

The basics out of the way, this then goes on to the meat of the idea:

A character is defined entirely (from a rules perspective that is) by what he can do, and how well he can do it. Thus the only way you can describe a character is by saying which actions he can perform and what modifiers he has to that action.

This suggests a more appropriate way of handling injury, magic, etc. Rather than having hit points, spell points, or the like you keep track of variable modifiers. The more injury is done to you, the higher the penalty to your physical actions (including remaining conscious, not dying, etc) becomes. The more spells you cast, the higher the penalty to casting further spells becomes. Encumbrance can be handled as a modifier which gives penalties to speed rolls, fatigue as a modifier which gives penalties to just about all rolls (except those to resist dying, bleeding, etc).

Another interesting extension of this is to magic items. Rather than having a limitation on how many items can be worn (as in D&D), items have to (in principle) make rolls to use their effect. Also, every item contributes to a 'magical load' penalty. Thus when you have lots of items (or several very powerful items) you have a worse magical load, causing some of the weaker items to behave unreliably or cease functioning altogether. Multiple magical items with the same effect as one larger one would contribute a greater magical load (thus discouraging one from wearing 5 rings of protection +10 in place of a ring of protection +50).

The obvious disadvantage of this system is that there is potentially a lot of rolling involved (and the rolling increases in tense situations, which you'd really want to streamline).

However, the major advantage of this is that it provides a mechanic that works in just about any situation, and is a rather coherent and straightforward underlying mechanic to implement.

I think the latter is a very important point, as it provides a unifying structure for the RPG rules set, and if the DCs, etc. are chosen well the former can be minimised somewhat.

[eef]

What's the modifier range of your characters?

If mods range from 1-100, then in any contest luck has just as much a part as skill.  This usually drives me nuts.

If mods have a broader range, then you have situations where A (mod 25) automatically loses to B (mod 150).  This may not be a bad thing; you've got a 'contest' range and a 'diceless' range.  Also, you'll have situations where characters will have to change the mod balance or they will lose.

[Ron Edwards]

Hello Kit,

The principles you're describing have been used in many, many games over the last ten-plus years. A couple of the earlier ones included Prince Valiant and Over the Edge, both of which opened a lot of conceptual doors for game designers after that.

I'm not even sure where to start in listing others ... for every one I list, ten will get unfairly left out. One of the most dramatic examples recently is HeroQuest.

Best,
Ron

[Kit]

What's the modifier range of your characters?

If mods range from 1-100, then in any contest luck has just as much a part as skill.  This usually drives me nuts.

If mods have a broader range, then you have situations where A (mod 25) automatically loses to B (mod 150).  This may not be a bad thing; you've got a 'contest' range and a 'diceless' range.  Also, you'll have situations where characters will have to change the mod balance or they will lose.

I haven't quite decided how big the modifiers will be in general, but I would expect a modifier of around 100 to represent someone who was rather well trained, but not ridiculously competent.

At low levels, luck will indeed be as great a portion of the contest as skill. That's more or less deliberate - until you're really good, luck plays a huge part in, for example, combat. Similarily I don't really have a problem with the notion that a master swordsman can wipe the floor with a rookie without even trying. A lot of the way of the system is set up is that you will often not need to roll, simply because the modifiers and DCs are so extreme. Seems reasonable to me that this should carry over into competitions as well.

ron edwards: Ah, well. I didn't think it was going to be that original. :) That being said, has heroquest had a new edition released? I don't remember the original working like this at all. Anyway, thanks for the examples. I'll see about trying to dig up a couple of them.

[Kit]

Hmm. Ok, upon investigation, the HeroQuest you're talking about is a completely different game from the one I was thinking of. They just happen to have the same name.

[John Uckele]

Just an idea: 1d100s are excessivly large. I'd sugest using a smaller (d20 or d12) die. D100 just gives you a very fine distinction (rolling 67 vs rolling 66) that doesn't need to be there (percentile systems use d100s for easy human comprehension). I think that instead of  modifiers in the range of +100 or more, you use a d12 (or d20 if you don't mind looking like a d20 cop-off) and make modifiers in the range of +12 instead.

[Kit]

The system was originally designed to use d20s, but I decided they didn't have the granularity needed because of other ways the system is set up.  I think that various things such as the magic system and the other variable modifiers need more fine tuned modifiers than a d20 allows.

When it comes to play testing I'll try it with both d20s and d100s as there's an easy conversion factor between the two, but for now I'm sticking with a d100 based system.

[Kit]

Incidentally, the system originally *was* a d20 knock-off. :) It started out life as an attempt to bolt on a character point based character creation system to d20, but after huge amounts of fiddling with appropriate house rules, etc. we decided that it had departed so far from d20 standard that we might as well take it apart and start from scratch as a new system.

[zephyr_cirrus]

As for the granularity "problems" with rolling a 66 and a 67, how often does life come down to the same type of situation?  And what are the odds of rolling two consecutive numbers?  About 1 in 5000?  I personally think that the d100 die mechanic is very useful and has lots of potential.

[ffilz]

Just an idea: 1d100s are excessivly large. I'd sugest using a smaller (d20 or d12) die. D100 just gives you a very fine distinction (rolling 67 vs rolling 66) that doesn't need to be there

A few comments on this statement:

First, the granularity of d100 can be advantageous if you use it to eliminate separate tracking of experience. For example, instead of needing 5 skill points to get a +1 on a d20 system, you could get a +1 on a d100 for every skill point. Now you don't have to track experience separately.

The advantage of easily understanding the percentages should not be discounted. RuneQuest works very nicely as a d100 system, even though the original RQ could have been done with a d20 (if they used the same crit confirmation that the D20 System uses). Of course later they brought in finer granularity.

A final comment is that sometimes you want events to have less than a 5% chance of occurring.

Kit - perhaps it would help if you explained more how your modifiers worked. I sense that part of your idea is to be able to assign a modifier for almost any circumstance, so you can use the finer granularity of d100 to have modifiers be just a +1% or so for those things everyone agrees should have some effect. Of course the question then is what does this do to handling time? It could reduce it if you can quickly say "Hmm, that should have an effect, +2" rather than trying to decide if te effect is big enough to justify a +1 on a d20.

Frank

[TonyLB]

If I could recommend, a quick scan of the past turns up some really interesting discussion on dice, granularity and certain fuzzy terms (notably "randomness").  These links leap out at me:

A Mathematician Speaks:  Rolling Dice
Terminology: Randomness
Linear Die Roll Modifiers are Broken

There's a lot of good, dense, crunchy thought there.  Lots of useful mental tools that can help you to analyze the situation.

[M. J. Young]

As for the granularity "problems" with rolling a 66 and a 67, how often does life come down to the same type of situation?  And what are the odds of rolling two consecutive numbers?  About 1 in 5000?

Welcome to The Forge, Zephyr.

Actually, the odds of two die rolls being consecutively increasing on d100 are 0.99%, or just one one hundredth of a percent lower than one in a hundred.

It's not that difficult to figure out, really. The odds of rolling any specified number is one in one hundred. The first roll can be anything, so the odds of it don't count. The question is what are the odds of the next roll being equal to the first roll plus one. It is impossible for the next roll to be one hundred plus one, so if the first roll is 100 it can't happen. Otherwise, whatever the first roll was, the odds are one in one hundred that the second roll will be one greater than it.

Approached more technically, there are ten thousand possible permutations of two rolls of d100, of which ninety-nine fit the description (the second greater than the first by exactly one), so the odds are ninety-nine in ten thousand, or nine-point-nine in one thousand, or point-nine-nine in one hundred.

Now, if you meant to ask what the odds were of rolling that exact combination, it's one in ten thousand. However, how many times do you roll the dice in your gaming career, and how many gamers are out there rolling dice? I'm sure it happens quite a bit, really.

--M. J. Young

[Kit]

Gosh. The thread lives. :-)

Just an idea: 1d100s are excessivly large. I'd sugest using a smaller (d20 or d12) die. D100 just gives you a very fine distinction (rolling 67 vs rolling 66) that doesn't need to be there

A few comments on this statement:

First, the granularity of d100 can be advantageous if you use it to eliminate separate tracking of experience. For example, instead of needing 5 skill points to get a +1 on a d20 system, you could get a +1 on a d100 for every skill point. Now you don't have to track experience separately.

Unfortunately this doesn't quite work. The problem is that modifiers are not all of equal utility, so you can't have one standardised cost for a +1 modifier. (Although actually experience isn't tracked as a seperate quantity, but is a property of specific modifiers - however the point remains that there needs to be some unit smaller than a +1 to measure it).

The advantage of easily understanding the percentages should not be discounted.

Yeah... unfortunately this isn't really percentile, because it's a roll over system. I have two excuses for this:

1) D20 origins.

2) Roll under systems irritate me. No good reason - I appreciate they make more sense in many ways, but they still do. I don't like the association of rolling low being good.

A final comment is that sometimes you want events to have less than a 5% chance of occurring.

No argument there. :-)

[/quote]
Kit - perhaps it would help if you explained more how your modifiers worked. I sense that part of your idea is to be able to assign a modifier for almost any circumstance, so you can use the finer granularity of d100 to have modifiers be just a +1% or so for those things everyone agrees should have some effect. Of course the question then is what
[/quote]

This is more or less correct. There will be a lot of things which will give one a slight advantage, and it's hard to quantify them all. A higher granularity allows one to get small edges which, while they're not going to win you the battle on their own, in the long run give you an advantage. A +1% is much more reasonable for something like this than a +5%.

Another thing I forgot to mention: This system allows arbitrarily high modifier stacking. There's no typing like in D20. The main area where this can present a problem is in the stacking of lots of small modifiers. If a small modifier is around 1 or 2% this is a much smaller danger than with a +5%.

does this do to handling time? It could reduce it if you can quickly say "Hmm, that should have an effect, +2" rather than trying to decide if te effect is big enough to justify a +1 on a d20.

Indeed. It should reduce handling time on circumstance modifiers, etc. A lot of the system is designed to have a coherent and easy to ad hoc rules set, and this is one aspect of that.

In terms of the problems you'd expect to arise with handling time of stacking modifiers, etc. I'm hoping to resolve some of that with appropriate character sheets and structuring the arrangement of the modifiers. It's going to be hard to tell until I get my act together and write this system into a play testable version though...