Quote from: BoxCrayonTales on July 19, 2022, 04:11:30 PMHow familiar are you with BRP? It already addresses the stuff you're bringing up. Or at least the 4e rulebook does. The SRD is crap.

I'm fairly familiar with older versions. Stormbringer was the 2nd campaign I ever ran and my Runequest game was my longest campaign before D&D 3e came out. I understand the BRP already does similar things to what I was talking about, but I find that converting success values into numbered successes, rather than named values, is much more flexible (as you can see in the James Bond 007 RPG). So instead of having a Attack and Defense Matrix like on page 193 of BRP 4e, you just subtract the target's successes from the attacker's. Plus, by having successes listed in numerical values, you can have a list of things to spend those successes on in resolution. For example, 1 success would do damage, but with 2 successes, you could do damage twice, or change the hit location and do damage, or trade both in for a Disarm effect, etc. I prefer systems where you spend successful rolls over system where you have to declare your special action (Called Shots, Disarm, etc) in advance as declaring in advance slows the game down.

For me it is all about speed of resolution and flexibility.

Quote from: jhkim on July 19, 2022, 04:37:10 PMhedgehobbit, are you familiar with the James Bond 007 RPG? That is percentile and has four levels of success very similar to what you suggest here. It has a varying multiplier for difficulty, though, which varies with the task.

Yes, as I mentioned in my previous post, this game is was what changed my mind on using multiples instead of +/- bonuses. The James Bond game was great but the fact that you have two different table lookups per roll was a bit much for me. It also bugged me that a Q4 success was worse than a Q1. They should have swapped those around.

Quote from: Stephen Tannhauser on July 16, 2022, 06:28:46 PM
The double-digit mental addition or subtraction required for modifiers which use increments of other than 5% or 10% (and if you don't use increments other than that, it's simpler to go to the d20, as noted)

Single-digit modifiers can be other than multiples of 5% and also not require double-digit addition or subtraction.

Quote from: Zelen on July 16, 2022, 02:59:11 PM
The d100 is just too big. Is there a meaningful difference between 71% chance of doing something, and a 74%?

There are two major ways I see single-digit modifiers used in percentile RPGs.

1) Cross-feeding. When a character has multiple skills that are applicable to a task, you use the highest and add 10% of the others. It is meaningful to players to know those additional skills count for something, so it does have meaning regardless of how insignificant it may seem to a given set of probabilities.

2) Sometimes the chance being adjusted is highly improbable to begin with. Most commonly, we're talking about "crits," when the percentile roll is under 1/10 the target number. When a small modifier adjusts the die roll rather than the target number, it has disproportionate sway on criticals. That could mean doubling or tripling the odds of a crit. It might also mean halving the odds, or even eliminating the possibility of a crit entirely. And it's hard to argue that's not meaningful.

Quote from: drayakir on July 18, 2022, 12:45:14 PM
Well, your counterpoint has several flaws.

I had points, plural. And "something you disagree with" is not what the word "flaw" means.

QuoteFirst off, you're just outright dismissing the fact that the d20 and d100 system in their most popular incarnations have an auto-pass and auto-fail number.

I wasn't dismissing anything at all. I was focusing on the games I know and play. And every feature I have brought up about d100 games that defeat your arguments appear in at least two different d100 RPGs that have been around for decades and were high profile at one time or another. You don't get to just ignore them. If your assertions are only true for certain RPGs, then it is only those RPGs that have the issues you're mentioning. Not d20 systems in general. Not d100 systems in general.

I mean you do realize CoC is a highly stylized game, right? Some would even say it's supposed to be biased towards making players lose. That makes it not a very good choice as a representative of all d100 games when the issue at hand is the rate of failure inherent in the d100 mechanic.

It's easy to name the most popular d20 system. 5E, of course. But again, we have a problem holding this up as representative of the d20 mechanic. The game was specifically designed with "bounded probability" in mind. It makes no sense to use that as an example when what we're discussing are the extreme ends of the probability distribution.

QuoteSo no matter how good you are, you have a 1% or 5% chance of just failing, regardless of how good you are. That's asinine. There's no reason that someone who is a grandmaster at riding horses is going to fail mounting a horse in ideal conditions. Just not going to happen. But the d100 and d20 system say that yes, you can have the most ideal conditions imaginable, but every 100 times you will fail every 100 times or every 20 times, depending on which system we're using.

Maybe you were referring to *the* d20 system? As in 3E/Pathfinder. That was the game that had Take 10, right? Where you can take the possibility of failure off the table entirely.

Or maybe you were referencing AD&D, where the riding proficiency specifically states you don't need to roll for mounting and dismounting. Success is automatic.

Was there another game that was the most popular incarnation of the d20 system that I missed that has grindmasher skill characters doing pratfalls?

QuoteAnd as far as Shadowrun goes, the scale is given as such: 1 is easy, 2 is average, 4 is hard, 6 is extreme. It is possible to have a target number above 6, but that's when there's an opposed check involved and someone rolled higher than 6. Then you need to match of exceed that. So, 6 successes means you can succeed at the most difficult task within the system. Which means that our human grandmaster has the following odds of success:

The probability of 6 successes or more is 31.0192476681325
The probability of 5 successes or more is 52.4499531567108
The probability of 4 successes or more is 73.8806586452891
The probability of 3 successes or more is 89.4666262733461
The probability of 2 successes or more is 97.2596100873746
The probability of 1 success or more is 99.6574512609218
The probability of no successes is 0.34254873907823

So let's see. Take the reciprocol, and it appears the grand poobah of riding in Shadowrun will be failing 1 in 292 times. Just FYI, if you tossed out the bounded probability in 5E, the best character under ideal circumstances would not only fail only on a 1, but would also have advantage. Meaning he'd have to roll a pair of 1's on 2d20. That's 1 in 400. Suddenly shadowrun guy is starting to look like a comedy relief sidekick.

QuoteThis makes much more sense than a flat failure/success rate of a single dice system.

How? And what is a flat failure? Near as I can tell, the numbers you produced only prove that at the end of the day it all comes down to a percentage. Meaning you can dice it by rolling a d100 with as many extra d10's as you want to have decimal places. No matter how many places you add, no matter how hi-res you want to go, it's still a linear distribution.

QuoteFurthermore, you keep saying that 1% or 5% is just graininess.

Do I keep saying that? Or did I point that out once?

QuoteThat's a great way to dismiss it, but it doesn't make sense. You said yourself that really our two numbers are 0 and 1, which I agree with. So with a dice pool system, I know that I'm going to succeed X%, but the d20 has a fuzziness rating of 10% (from the 1 and 20 face) and the d100 has a fuzziness rating of 2% (the 1 and 100 faces). Would it not be better to have something with no fuzziness?

What's fuzzy?

Every RPG I've ever played or run has things in it that are 0 and 1 probability. Often they're things you just don't roll for. But I have no problem with a mechanic that allows skill and circumstance to add up to high enough (or low enough) that the chance of success is 100% or 0%. Which you do find in AD&D 1E by the way. The six repeating 20's meant some ACs could be impossible to hit. There could be auto-success on item saves. Or is that not a popular enough d20 system to talk about?

QuoteThe answer is yes. There are only disadvantages to using a single die over a dice pool.

I think you were successful in your analysis but you needed 3 successes to be right.

I honestly think it's because writers think they're being clever by using dice in non-traditional ways than just rolling and adding them up. 

I've seen games that use D6's, and count up "successes" that are 4, 5, and 6.   It could be replicated by tossing coins and count how many came up heads. 

Hell, I toyed with making a rules lite game using just a 1D10.  Why?  Because a +1 on a D20, aka 5%, isn't enough of a bonus to me to "feel" significant.  Also, you could play the game using a deck of cards with the face cards and jokers taken out.  It's not logical to play that way, but it does make it a bit interesting to some people like me.  Or because it's different.  No more than that.  It's just different. 

Quote from: Jam The MF on July 15, 2022, 07:13:11 PM
Having a % Chance of Being Successful at "X", is a very natural way of explaining things.

Why haven't Percentile-Based Systems won out in a big way, in the RPG market?

Thanks in advance, for chiming in.

A percentage system does have the advantage of being clear about the chance of success vs failure but sometimes the degree of success or failure is important. In other situations an opposed roll is necessary. On other occasions there isn't one stat or characteristic or skill that is appropriate to test against but a combination. Percentile systems have methods and tools to incorporate these things but it does leave things open for alternative rules.

Similarly the theme of the game may lend itself to a different system.

In truth I am a pretty big fan of percentile systems. 

Quote from: drayakir on July 15, 2022, 10:23:04 PM
Well, I mean I suppose you could have a percentile system that doesn't use a d100, but... I dunno. The problem with the d100 and the d20 that at a certain point your skill/stat doesn't matter. If the target number is 13, and you're at +6, you have very good odds of it, but there's still a decently high chance that you will fail. More, you still run the risk of failing really easy tasks that somebody at your skill level has no business failing. That's why I prefer bell curve stuff, since that distribution is more like a realistic skill distribution.

It's not "swingy" if you can think in terms of probability. If you want less swingy games, start with higher probabilities. Like most things in % games this is remarkably simple. The problem occurs when someone thinks rolling an 18 on 3D6 is toughly the same as rolling a 20 on a d20.

A skill of 19 out of 20, or 95%, or 15 or below on 3D6 means roughly the same: you have about 5% chance of failure. Any bell curve could be calculated as a percentage too. The difference being that a +1 bonus will count differently based on where you are in the 3D6 curve. If you need to roll an 18 on 3D6 a +1 gives roughly +1.4%. If you need an 11 on 3D6 a +1 increases the chance by 12.5%. If you need to roll 100 on % dice a + 5% increased the chance exactly that much.

The real difference is that 3D6 is a bit more confusing to calculate, but to some people it's more fun.

Quote from: Lunamancer on July 19, 2022, 06:35:04 PM
reciprocol,

Reciprocal.

Also, take 10s are an optional rule. And yes, the systems you're shilling for have a flat failure percent.

Quote from: weirdguy564 on July 20, 2022, 08:59:20 AM
I honestly think it's because writers think they're being clever by using dice in non-traditional ways than just rolling and adding them up. 

I've seen games that use D6's, and count up "successes" that are 4, 5, and 6.   It could be replicated by tossing coins and count how many came up heads. 

Hell, I toyed with making a rules lite game using just a 1D10.  Why?  Because a +1 on a D20, aka 5%, isn't enough of a bonus to me to "feel" significant.  Also, you could play the game using a deck of cards with the face cards and jokers taken out.  It's not logical to play that way, but it does make it a bit interesting to some people like me.  Or because it's different.  No more than that.  It's just different.

Both of these die mechanics have been around and used in multiple games (some of them fairly popular, like Shadowrun and Cyberpunk) since at least the 90s or late 80s. Neither is new or different. Some people just like it better than rolling % or d20s.

Quote from: drayakir on July 20, 2022, 11:13:19 AM
Also, take 10s are an optional rule.

LOL. Anything to avoid admitting you straight up have no clue what you're talking about.

QuoteAnd yes, the systems you're shilling for have a flat failure percent.

I haven't shilled for any system; and you still haven't explained what "flat failure" even means.

Quote from: drayakir on July 20, 2022, 11:13:19 AM

Quote from: Lunamancer on July 19, 2022, 06:35:04 PM
reciprocol,

Reciprocal.

Also, take 10s are an optional rule. And yes, the systems you're shilling for have a flat failure percent.

You do realize that in 5E only attack rolls have the 1 and 20 autofail/autosucceed, right? 
For ability checks (skill checks or raw attribute checks) and saving throws you just roll and add and what you get is what you get.

Quote from: Lunamancer on July 20, 2022, 11:56:27 AM

Quote from: drayakir on July 20, 2022, 11:13:19 AM
Also, take 10s are an optional rule.

LOL. Anything to avoid admitting you straight up have no clue what you're talking about.

QuoteAnd yes, the systems you're shilling for have a flat failure percent.

I haven't shilled for any system; and you still haven't explained what "flat failure" even means.

A "flat failure" is when you automatically fail when the dice displays a certain number.

Quote from: moonsweeper on July 20, 2022, 12:02:22 PM

Quote from: drayakir on July 20, 2022, 11:13:19 AM

Quote from: Lunamancer on July 19, 2022, 06:35:04 PM
reciprocol,

Reciprocal.

Also, take 10s are an optional rule. And yes, the systems you're shilling for have a flat failure percent.

You do realize that in 5E only attack rolls have the 1 and 20 autofail/autosucceed, right? 
For ability checks (skill checks or raw attribute checks) and saving throws you just roll and add and what you get is what you get.

Immaterial. An attack is still a dice roll.

Quote from: Trond on July 20, 2022, 09:55:13 AMThe real difference is that 3D6 is a bit more confusing to calculate, but to some people it's more fun.

I found this to be a double edge sword. On one hand, if the probabilities are clear, some players will base their character's action on the probability of success instead of any other story-based reasons, OTOH, if the probabilities are not clear, other players will do incredibly stupid (i.e. suboptimal) things because they don't realize how low their chance of success will end up being.


However, the biggest downside to having to roll multiple dice for each action is what happens if you have to roll for 15 goblins. A single die is much faster in this case. So much so that some games discourage the use of large mobs just to have the game function. IMO, this is too limiting as far as adventure design goes. Even percentage dice can be bulk rolled as you only need to roll the ones dice if the tens dice is in question. For example, if your chance of success is 55 then you only need to roll the ones dice if the tens dice is a 5.

Quote from: drayakir on July 20, 2022, 01:20:49 PM

Quote from: Lunamancer on July 20, 2022, 11:56:27 AM

Quote from: drayakir on July 20, 2022, 11:13:19 AM
Also, take 10s are an optional rule.

LOL. Anything to avoid admitting you straight up have no clue what you're talking about.

QuoteAnd yes, the systems you're shilling for have a flat failure percent.

I haven't shilled for any system; and you still haven't explained what "flat failure" even means.

A "flat failure" is when you automatically fail when the dice displays a certain number.

Quote from: moonsweeper on July 20, 2022, 12:02:22 PM

Quote from: drayakir on July 20, 2022, 11:13:19 AM

Quote from: Lunamancer on July 19, 2022, 06:35:04 PM
reciprocol,

Reciprocal.

Also, take 10s are an optional rule. And yes, the systems you're shilling for have a flat failure percent.

You do realize that in 5E only attack rolls have the 1 and 20 autofail/autosucceed, right? 
For ability checks (skill checks or raw attribute checks) and saving throws you just roll and add and what you get is what you get.

Immaterial. An attack is still a dice roll.

Actually, it is completely 'material' since the items in discussion (ride check to mount a horse and 'taking 10') are specifically skill checks and you brought up 'ideal conditions'.  Attack rolls obviously will have some chance of failure because the PC is under some form of 'stress' during a fight since conditions are never 'ideal' in combat.

Throughout this thread a number of people have indicated that they tend to think in probabilities.  In the case that you KNOW a probability that can be easy to do.  On the other hand, frequently in the game you're asked to create a situation in which you don't know what the probability ought to be. 

Is throwing a grappling hook against a 40' tower significantly different than throwing it against a 20' tower?  If I have an 85% in grapple hooking, does that mean it applies equally to both situations?  Or is one of them 'normal' and I get a +20%/-20% in the other?  What does it mean if I have an 85% in a skill, but I'm also using the skill at -30% or -40%? 

Most people have trouble thinking in probabilities, and comparing relative abilities of different people meaningfully is hard (as has been described above).  If I think that Bruiser the Door Buster has a 95% chance of breaking a door, and Poindexter is half as strong, do I think he should have a 45% chance, or 0%. Is there any skill involved or is it all attribute based?  What if Poindexter is trying to hold the door closed? 

Assigning a fixed TN without considering any of the individuals and then letting them apply their relevant abilities tends to be easier for most people.  If I say that breaking down a door is a TN 20, and someone holding the door is usually a -4, but someone weak and frail only counts as a -2, a lot of players will nod and agree and we haven't even calculated the probabilities yet.  But Bruiser knows he needs a 22; he probably knows he gets a +8 on his roll, and he's going to look for additional bonuses (like a running start or using a statue as a battering ram).  That may not actually reflect what I think the odds ought to be if I carefully considered them, but it works pretty quickly, and if the situation changes (now Poindexter is trying to break down the door and Bruiser is holding it) it's really easy to modify on the fly - the DC is now 24 (stronger person holding) and Poindexter only has a +4 - he's also going to want to look for some situational modifiers. 

Quote from: deadDMwalking on July 20, 2022, 03:15:15 PM
Throughout this thread a number of people have indicated that they tend to think in probabilities.  In the case that you KNOW a probability that can be easy to do.  On the other hand, frequently in the game you're asked to create a situation in which you don't know what the probability ought to be.

Is throwing a grappling hook against a 40' tower significantly different than throwing it against a 20' tower?  If I have an 85% in grapple hooking, does that mean it applies equally to both situations?  Or is one of them 'normal' and I get a +20%/-20% in the other?  What does it mean if I have an 85% in a skill, but I'm also using the skill at -30% or -40%?

Most people have trouble thinking in probabilities, and comparing relative abilities of different people meaningfully is hard (as has been described above).  If I think that Bruiser the Door Buster has a 95% chance of breaking a door, and Poindexter is half as strong, do I think he should have a 45% chance, or 0%. Is there any skill involved or is it all attribute based?  What if Poindexter is trying to hold the door closed?

Assigning a fixed TN without considering any of the individuals and then letting them apply their relevant abilities tends to be easier for most people.  If I say that breaking down a door is a TN 20, and someone holding the door is usually a -4, but someone weak and frail only counts as a -2, a lot of players will nod and agree and we haven't even calculated the probabilities yet.  But Bruiser knows he needs a 22; he probably knows he gets a +8 on his roll, and he's going to look for additional bonuses (like a running start or using a statue as a battering ram).  That may not actually reflect what I think the odds ought to be if I carefully considered them, but it works pretty quickly, and if the situation changes (now Poindexter is trying to break down the door and Bruiser is holding it) it's really easy to modify on the fly - the DC is now 24 (stronger person holding) and Poindexter only has a +4 - he's also going to want to look for some situational modifiers.

I agree a lot of people don't understand probability. I don't blame them, it's not a simple topic. And I'm far from an expert, but I distinctly recall my university stats professor's rant about how probability is widely misunderstood and one of the most common misunderstandings is that you must have a significant number of samples for the whole idea of probability to have any meaning. n = 100 at a minimum.

So, for one-off events, like bashing a door down or things you might do a few times in a campaign, probability is a meaningless concept. The number you pick really doesn't matter much. People have a hard time wrapping their head around this. A single die roll is deterministic and its outcome is predicable, you just don't know it yet. So the best thing to do is treat one-off probabilities as a form of expression that emphasizes game fluff, setting, and character. Poindexter gets -40% penalty to bashing the door down because he's just that much of a weakling. Or, if you prefer negotiating for bonuses in d20 land, it's the same thing. It helps players create a clear image of the situation and their character.

For repeated events where a trend is observable, such as weapons use, probability starts to mean something. Performing a significant number of rolls, which individually may be deterministic, gives meaning to probability. However, repeated events like combat actions are normally very well covered by the rules with set bonuses and penalties and likely subject to extensive play testing to get the right feel. If attacking from behind gives you +50%, you will notice the benefit of such dishonorable tactics after a few sessions.