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Talakeal
2015-01-08, 05:41 PM
So last week my DM announced that he wanted to start using this mechanic for rolling dice:


This dramatic curve resolves any flatness that plagues your current system.
Copy this free text. Practice. Enjoy your refreshed role-playing experience.
Add 3D6, using the "1", "6", Double, and Triple modifiers below. Enjoy!
•A Triple "1" causes a Doomed (Worst) result, where the Worst Possible Thing happens. Chat and let the referee decree.
•A Double "1" causes an Epic Failure (Fumble, Gaffe). Something painful, shameful, and probably quite expensive happens.
•A non-cancelled "1" is Bad Karma. This never adds to the total; it lurks and cancels any benefit of a Double or a "6" result.
•"1" and "6" die results cancel, fusing into a single "5" that might Double with another "5" for a final total of 11.
•A non-cancelled "6" is Good Karma. Its value is added in as usual, then it increases the final value of the roll by 2 points.
•Doubles (between 2 and 5) add 1 point to the total. If the third die is a "1", no bonus point - but with a "6", 3 points are added!
•Triples (between 2 and 5) add 3 to the total. That's it, unless they are all "1" (Doomed) or "6" (Glory) results.
•A Double "6" produces an Epic Win (Critical, Superior), with enhanced results specific to your game system.
•A Triple "6" produces Glory (Best), where the Best Possible Thing happens. Chat and let the referee decree.
http://un-twenty.com/

I had never heard of it before, and a quick Google search didn't turn up anything, so I thought I would ask the playground what their opinion of it is?

Anyone have any thoughts? Ever seen it before? Ever tried using it? Seen any discussion on it?

Beta Centauri
2015-01-08, 06:03 PM
Probably fine. I'd recommend making the bad results as interesting for the players as the best results, but I suppose that's what the chat is about.

Mando Knight
2015-01-08, 06:18 PM
I feel like the effect of a 1 is possibly a bit too polarizing, and may bring down the expected average, even if other doubles and triples bring it up. The chance of something bad happening for the player is increased compared to normal d20 systems, where a 1 is just a simple failure: now you have the chance of a simple failure (at best) on double 1s, as well as spectacular failure as a 1/216 chance.

Talakeal
2015-01-08, 06:27 PM
I feel like the effect of a 1 is possibly a bit too polarizing, and may bring down the expected average, even if other doubles and triples bring it up. The chance of something bad happening for the player is increased compared to normal d20 systems, where a 1 is just a simple failure: now you have the chance of a simple failure (at best) on double 1s, as well as spectacular failure as a 1/216 chance.

Agreed.

Note, however, that every game I play in has house rules for fumbles and critical. The game I am a PC in rules that any roll of a 1 is an automatic fumble and any roll of a 20 is an automatic critical regardless of circumstances. The game I am running, on the other hand, uses auto success / failure on a nat 1 or 20 and then if it is confirmed will upgrade it to a critical hit or fumble, and this applies to all d20 rolls not just combat.

Mando Knight
2015-01-08, 06:47 PM
Agreed.

Note, however, that every game I play in has house rules for fumbles and critical. The game I am a PC in rules that any roll of a 1 is an automatic fumble and any roll of a 20 is an automatic critical regardless of circumstances. The game I am running, on the other hand, uses auto success / failure on a nat 1 or 20 and then if it is confirmed will upgrade it to a critical hit or fumble, and this applies to all d20 rolls not just combat.

Reading it over, it looks like this system puts the uncancelled double-1s (rough estimate, >5% chance of occurrence) at fumble and Super Fumble at 1/216: it's strictly more dangerous to the player than a d20 system where a 1 is a guaranteed fumble and "double" fumbles (1/400 chance) are Super Fumbles. Now, while these chances are reflected on the Critical Success end, the chances of a party meeting its premature end is a bigger threat than a couple of goblins or kobolds falling on their own crudely-made spears, and is amplified wherever there's a class that is allowed success without risking bad rolls on their own part while another class relies on multiple rolls to meet quota (i.e. D&D 3.5 or Pathfinder).

I would not use the system, simply for the fact that the stated effects of some of the outcomes greatly exceed the probability of their occurrence (that is, 1/216 chance on every roll for a potentially-lethal failure). It may have a place in high-risk/high-reward situations (i.e. anything that involves something like summoning or making pacts with powerful but capricious and malevolent entities such as demons), but not in "normal" or "heroic" circumstances.

MKV
2015-01-08, 07:06 PM
One thought I have is that it seems like a rather complected mechanic for such a commonly used action. Sure you can argue that it will become simple with time but that doesn't change the fact that these modifiers will be a pain to remember for ages to come. Another thought is that this changes the game mathematically which will no doubt affect the game regardless of the level of thought put into this system there is no way you can account for the impact of changing such a commonly used mechanic as rolling a d20. On a related note what is the point of this? To add more critical hits and misses to the game? If that is the case why not try something like this (http://deltasdnd.blogspot.com/2012/07/critical-hits.html). Lastly the d20 is such a unambitious symbol of our hobby and I would miss it if it were replaced by something so... so... plebeian as 3d6.

Talakeal
2015-01-08, 07:09 PM
One thought I have is that it seems like a rather complected mechanic for such a commonly used action. Sure you can argue that it will become simple with time but that doesn't change the fact that these modifiers will be a pain to remember for ages to come. Another thought is that this changes the game mathematically which will no doubt affect the game regardless of the level of thought put into this system there is no way you can account for the impact of changing such a commonly used mechanic as rolling a d20. On a related note what is the point of this? To add more critical hits and misses to the game? IF that is the case why not try something like this (http://deltasdnd.blogspot.com/2012/07/critical-hits.html). Lastly the d20 is such a unambitious symbol of our hobby and I would miss it if it were replaced by something so... so... plebeian as 3d6.

I THINK he is trying to make the system less random and swingy, so the dice will have more of a bell curve and natural 1s and 20s will occur less often.

Overall I think it might be a good idea, but I imagine it would be very tedious if rolling multiple dice. A high level monk performing a flurry of blows is cumbersome enough as is, but doing it on 3d6 per attack? Ouch.

The Grue
2015-01-08, 07:20 PM
I THINK he is trying to make the system less random and swingy, so the dice will have more of a bell curve and natural 1s and 20s will occur less often.

If that's what he's trying to do, then he's shot himself in the foot with the nat 1/nat 6 effects. That system is even more swingy than rolling a D20.

Mando Knight
2015-01-08, 07:53 PM
I THINK he is trying to make the system less random and swingy, so the dice will have more of a bell curve and natural 1s and 20s will occur less often.

Except they won't. If you assume a double-1 is equivalent to a natural 1 (it's described as a "fumble" in the thing) on a d20, ignoring the cancellation there's a greater than 6% chance of a fumble (or critical) with this system. Even considering the cancellation system, which is 1/5 of the double-1/double-6 cases, that means a (roughly) 5.56% chance each of "simple" crit/fumble, plus the 1/216 chance each of a "Super" crit/fumble off of triple-1/triple-6 (compared to double-1 or double-20 on a d20, which is 1/400).

With the complexity of the bonuses for 6s and the other doubles/triples, and the 1s having an effective value of less than 0, it'd take someone with a much better head for statistical analysis than I to make heads or tails of the new probability curve, and I can't tell you the average (which for 3d6 and d20 both is 10.5).

Hytheter
2015-01-08, 08:00 PM
This seems unnecessarily complicated and without seeing a probability distribution I'd guess that it's pretty inconsistent and strange. Maybe a weirdly deformed bell curve? edit: No that can't be right... fiddling in excel now trying to find the answer. I'm pretty sure it's impossible to roll a 2 which is an odd quirk.

Hytheter
2015-01-08, 09:13 PM
I was bored
http://i.imgur.com/is6P6o6.png
Basically the distribution is retarded. It's vaguely bell curve-like, but jagged and uneven with huge spikes at each end. Incidentally each end is where the guaranteed successes/failures occur, which has the effect of trivialising roll modifiers.
It's only marginally less swingy than a d20 in the middle section, and the spikes at the ends basically bring it up from "fairly" to "hella" swingy.

It's very uneven, hella swingy and unnecessarily complicated; highly unappealing in pretty much any circumstance.

If you want a bell curve just use 3d6 and drop DCs by 1 or 2.

Jay R
2015-01-08, 09:46 PM
I agree that the d20 system is too simplistic. It assumes that all skills work the same. For instance, that a person with a little knowledge might know a fact that a person with a lot of knowledge might not, with exactly the same likelihood that a weak person could do a feat of strength that a strong person could not. This is obviously untrue. And that an additional amount of skill will help a weak person by exactly the same proportion that a similar increase will help a strong one (i.e., that all skills are linear).

But it does no good to replace a simplistic and inaccurate simulation with another just as simplistic and inaccurate.

It produces a slight increase in fumbles and crits - 6% chance of either. Easy rolls have become easier; harder rolls are harder.

The probability of any roll or higher is as follows:
4 94.0%
5 92.6%
6 88.4%
7 84.3%
8 75.9%
9 67.6%
10 56.0%
11 50.5%
12 42.1%
13 36.1%
14 29.2%
15 23.6%
16 14.8%
17 12.0%
18 7.9%
19 7.4%


I don't have time to check my work, so these numbers are not guaranteed.

So, for instance, getting a 16 or better under the new system is about as hard as getting an 18 in the old system. Meanwhile, getting a 7 under the new system is no harder than getting a 4 under the old. Also, note that the curve is not smooth; there is not much difference between needing a 16 or a 17, but a very large difference between needing a 15 or a 16.

Nagash
2015-01-11, 11:22 PM
seems like a lot of unnecessary complication.

If he wants to change critical rules based on dice why not go grab some of the dice from the newest warhammer rpg and use those alongside a D20. Just roll a couple of them in addition and modify the result accordingly.

Knaight
2015-01-12, 12:09 AM
This is a pointlessly convoluted system, and there's little to no benefit out of it. Worse, the way it is implemented has the goals directly working in opposition to each other. The entire point of relatively loosely defined extreme failure and complication systems is that it adds something to the game at minimal mechanical cost, the introduction of a bunch of fiddly modifiers undoes that. A large part of the reason for a multiple die mechanic is to introduce a controlled curve of some sort, but this isn't that. There's also a system there which differentiates between different versions of the same number, which can be nice for variation, but then that doesn't happen.

By contrast, here's what a more competent mechanic looks like: Shadowrun uses a dice pool system, where you roll a bunch of dice and need a certain number of 5's and 6's. If you get enough to succeed, but over half of your pool is a 1, you get a complication. Less trained characters are more likely to have these happen, it's a simple mechanic that doesn't interfere with other things, and it works with everything else in the system. It's simple, it's elegant, it doesn't involve a bulleted list of 9 little rules for rolling the dice.

Now, there are some interesting concepts in this that could work. For instance, the degrees of critical failure based on number of instances of the worst roll is an interesting concept, and in a system which uses fewer rolls having them be a bit complex isn't even necessarily bad. The implementation is just terrible. It would be way easier to roll 3d20 and always take the median, then have a complication if the lowest die is a 1, a beneficial side effect if the highest die is a 20, a critical failure/success with 2 1's or 20's, and "The Best Thing" and "The Worst Thing" saved for a triple. This actually has more variations on outcome (such as having both a beneficial side effect and a complication on the same roll), and is vastly simpler. It's also an example I literally made up while writing this paragraph, and not something that was posted on its own web page with some self-aggrandizing text about its greatness; the mechanic is still a bit clunky in anything with the sheer number of rolls as D&D.

Joe the Rat
2015-01-12, 11:01 AM
Now, there are some interesting concepts in this that could work. For instance, the degrees of critical failure based on number of instances of the worst roll is an interesting concept, and in a system which uses fewer rolls having them be a bit complex isn't even necessarily bad.

This is the part I found potentially interesting, and the best innovation over the "simple" 3d6 bell curve alternative. The number of 1s and 6s gives you the Weals and Woes of a success or failure.

Here's what I would do with it. Have 1-1-2 to 1-1-5 be critical failure IF it would fail anyway, and 1-1-1 being Always Fail / Epic Fail. Conversely, 6-6-2 to 6-6-5 would be a critical success IF it would be a successful result anyway, and 6-6-6 being Auto-Success / Epic Glory. This would actually broaden the "range" where criticals could occur, making frequency dependent on your ability (the skill modifier that determines how low you can roll and still have a success. That should be 4/216 potential crits, and 1/216 auto crits on each end, if I'm doing my probabilities right. If you want to make this easier to track, allow 1-1-6 as a potential crit fail and 6-6-1 as a potential crit success, giving you 5/216 potential crits and 1/216 auto crits... which maximizes to 1/36 if the entire range qualifies (if a 13 would hit, all 6-6-x are crits. if you need a 9 or better, all 1-1-x are crit fails). You could extend this to all triples being critical, giving you another 4/216 critical result options (good OR bad) that depend entirely on success/failure of the result.

Reverse the scale (1's are good, 6s are bad), and you could use it with any of the 3d6 under games like GURPS.

This setup rewards the highly skilled, as they have a better chance of critical success (more of the 3d6 totals are successes, so more of the triples and 6-6-x combinations will be successful results, and be crits are the good kind), while an untrained character trying the same difficulty of task is more likely to muck things up. An even split gives you 8/216, or 1/27 crit+ results (and an equal number of crit-). At your best (a roll of 6+ succeeds), you have 11/216 critical result options (5.09%, slightly better than 1/20). So on the whole this makes critical results less likely, which better fits the whole "normalized results / skill matters more" approach.

Segev
2015-01-12, 11:13 AM
I'm with others on this being too complicated and too likely to emphasize auto-successes and auto-failures. This is particularly egregious with skill checks, which, in d20, are never assumed to auto-crit or auto-fail. A natural "1" that still beats the DC still succeeds, and a natural "20" that still fails to meet the DC still fails.

If he just wants more of a bell curve, he could roll 3d6 plus 2 Fudge Dice. Fudge Dice are, essentially, d2s that have possible results of "+1" and "-1."

3d6 produces a range of 3 to 18. Two Fudge Dice make it possible for that to get as low as 1 (3 "1s" and 2 "-1s") and as high as 20 (3 "6s" and 2 "+1s"), with every number between being possible. It's a smoothe bell curve with 11.57% chance of getting a 10, .35% chance of getting a 2, and .12% chance of getting a 1. Mirrored, so 11, 19, and 20 have the same probabilities, respectively.

Edit to add: You can simulate Fudge Dice by just declaring two clearly-different-from-the-3d6 dice to be them, and using even = -1 and odd = +1, or the like.

ewoods
2015-01-12, 12:46 PM
Reminds me vaguely of Savage World's "acing" mechanism. Roll a d6. If it's a 6, roll again and add the result. If it's another 6, roll again and add the result. Ad infinitum. Likewise, if it's a 1, that's an automatic failure. Roll again and if it's another 1, that's a critical failure.

Personally, I think any system that increases the number of dice being rolled and the amount of numbers to be added together just slows down the system, especially in combat. If you're rolling 3d6 just to see if you hit, and there are four players, each with 3 attacks per round, that's 36 dice being added up each round.

Ravens_cry
2015-01-12, 12:51 PM
Well, it's certainly an untwenty system, I will grant you that. It's everything that d20 is not, including the good things.

obryn
2015-01-12, 01:22 PM
Goodness, I supposed it could have been made more fiddly, but I'm not exactly sure how. Hi there, unnecessary complexity!

For a game like D&D where there's dozens of 'd20' rolls per game, this seems like a terrible idea.

1337 b4k4
2015-01-12, 03:18 PM
So just for fun, I think I've got an Anydice program that simulates this "untwenty" system and ... well ... :smalleek:

For those of you so inclined, here's the link (http://anydice.com/program/5065)

And for those of you really inclined, here's the source, commented. If you see any mistakes let me know:




function: triples A:s {
if [count 2 in A] = 3 {
result: 1
} else if [count 3 in A] = 3 {
result: 1
} else if [count 4 in A] = 3 {
result: 1
} else if [count 5 in A] = 3 {
result: 1
} else {
result: 0
}
}

function: doubles A:s {
if [count 2 in A] = 2 {
result: 1
} else if [count 3 in A] = 2 {
result: 1
} else if [count 4 in A] = 2 {
result: 1
} else if [count 5 in A] = 2 {
result: 1
} else {
result: 0
}
}

function: untwenty T:s {
X: 1@T
Y: 2@T
Z: 3@T
Q: {}


if X = 6 { \If the first value is a 6, evaluate for 1's\
if Y = 1 {
Q: {0, 5, 0} \X becomes 0 since it's canceled, and Y becomes 5 since that is what was canceled with\
Y: 5 \Prevents further use of the 1 in this slot\
} else if Z = 1 {
Q: {0, 0, 5} \As above, but for the Z value\
Z: 5
} else {
Q: {X, 0, 0} \If neither Y nor Z is a 1
}
} else if X = 1 { \Logic as above, but swapping 1's and 6's\
if Y = 6 {
Q: {0, 5, 0}
Y: 5
} else if Z = 6 {
Q: {0, 0, 5}
Z:5
} else {
Q: {X, 0, 0}
}
} else {
Q: {X, 0, 0} \X is neither 1 or 6\
}


if 2@Q = 0 { \If slot 2 has not be assigned a value, evaluate Y\
if Y = 1 { \If Y is 1, evaluate for 6's, since we've already evaluated X, we only need to look at Z\
if Z = 6 {
Q: {1@Q, 0, 5} \ Keep the value in slot 1, and perform logic as above in the X evaluation\
} else {
Q: {1@Q, Y, 3@Q}
}
} else if Y = 6 { \As above, swap 6's and 1's\
if Z = 1 {
Q: {1@Q, 0, 5}
} else {
Q: {1@Q, Y, 3@Q}
}
} else {
Q: {1@Q, Y, 3@Q} \Y was not a 6 or a 1\
}
}

if 3@Q = 0 {
Q: {1@Q, 2@Q, Z} \If no value assigned to slot 3, put Z in this slot \
}


A: [count 1 in Q] \Count the number of 1's\
B: [count 6 in Q] \Count the number of 6's\


if A = 3 {
result: -30 \Triple 1's, super epic fail\
} else if A = 2 {
result: -25 \Double 1's, epic fail\
} else if B = 3 {
result: 30 \Triple 6's, super epic win\
} else if B = 2 {
result: 25 \Double 6's, epic win\
} else if [triples Q] = 1 {
result: Q + 3 \Triples, 2-5\
} else if [doubles Q] = 1 {
if A = 1 {
result: Q - 1 \Doubles with a 1, no bonus and the 1 doesn't count\
} else if B = 1 {
result: Q + 3 \Doubles with a 6, plus 3!\
} else {
result: Q + 1 \Doubles, plus 1\
}
} else {
result: Q \Everything else, just sum the result\
}
}




Interesting results:
You can't roll below a 4
You can't roll a 5
You can't roll a 16
You can't roll a 20


Suffice to say, I don't think this will get quite the results your DM wants. It will curve the results a bit, but that could be easily accomplished just by requiring more roles to succeed (see 4e skill challenge).

obryn
2015-01-12, 03:40 PM
So let's sum all this up as, "Whoever made this didn't do the first bit of checking on their math, like so many other amateur and (sadly) professional RPG designers."

Jay R
2015-01-12, 10:52 PM
It is overly convoluted.
It adds complexity without clarity.
Its effects are not clearly understood.
It is intended to solve a problem that is not well defined.

Gygax would have loved it.

Hytheter
2015-01-13, 05:30 AM
Interesting results:
You can't roll below a 4
You can't roll a 5
You can't roll a 16
You can't roll a 20

I think you messed up.
You can roll a 5 by rolling 1 6 6 1. The one and the six "cancel" and become 5. The remaining 1 adds no points but adds "bad karma" which does nothing in this case. You can also get it from 1 2 3; 2+3=5 and the 1 isn't counted.
3 5 6 makes 16; 3+5+6=14, and rolling a 6 adds 2 to the total to make 16.

edit: fixed typo

Nagash
2015-01-13, 05:49 AM
Gygax would have loved it.

The 2nd most damning thing possible to say about a mechanic.

The first being "Rifts did it"

1337 b4k4
2015-01-13, 03:38 PM
I think you messed up.
You can roll a 5 by rolling 1 6 6. The one and the six "cancel" and become 5. The remaining 1 adds no points but adds "bad karma" which does nothing in this case.

There's no remaining 1. 1 and 6 cancel to give 5 leaving 5 and 6 which total to 11. Have to assume you meant 6 1 1 in which case on a re-read you're right. Same with the 1 2 3



3 5 6 makes 16; 3+5+6=14, and rolling a 6 adds 2 to the total to make 16.

Again, you're right, I missed that.


Edit:
--------

Updated AnyDice (http://anydice.com/program/5084)



function: triples A:s {
if [count 2 in A] = 3 {
result: 1
} else if [count 3 in A] = 3 {
result: 1
} else if [count 4 in A] = 3 {
result: 1
} else if [count 5 in A] = 3 {
result: 1
} else {
result: 0
}
}

function: doubles A:s {
if [count 2 in A] = 2 {
result: 1
} else if [count 3 in A] = 2 {
result: 1
} else if [count 4 in A] = 2 {
result: 1
} else if [count 5 in A] = 2 {
result: 1
} else {
result: 0
}
}

function: untwenty T:s {
X: 1@T
Y: 2@T
Z: 3@T
Q: {}


if X = 6 { \If the first value is a 6, evaluate for 1's\
if Y = 1 {
Q: {0, 5, 0} \X becomes 0 since it's canceled, and Y becomes 5 since that is what was canceled with\
Y: 5 \Prevents further use of the 1 in this slot\
} else if Z = 1 {
Q: {0, 0, 5} \As above, but for the Z value\
Z: 5
} else {
Q: {X, 0, 0} \If neither Y nor Z is a 1\
}
} else if X = 1 { \Logic as above, but swapping 1's and 6's\
if Y = 6 {
Q: {0, 5, 0}
Y: 5
} else if Z = 6 {
Q: {0, 0, 5}
Z:5
} else {
Q: {X, 0, 0}
}
} else {
Q: {X, 0, 0} \X is neither 1 or 6\
}


if 2@Q = 0 { \If slot 2 has not be assigned a value, evaluate Y\
if Y = 1 { \If Y is 1, evaluate for 6's, since we've already evaluated X, we only need to look at Z\
if Z = 6 {
Q: {1@Q, 0, 5} \ Keep the value in slot 1, and perform logic as above in the X evaluation\
} else {
Q: {1@Q, Y, 3@Q}
}
} else if Y = 6 { \As above, swap 6's and 1's\
if Z = 1 {
Q: {1@Q, 0, 5}
} else {
Q: {1@Q, Y, 3@Q}
}
} else {
Q: {1@Q, Y, 3@Q} \Y was not a 6 or a 1\
}
}

if 3@Q = 0 {
Q: {1@Q, 2@Q, Z} \If no value assigned to slot 3, put Z in this slot \
}


A: [count 1 in Q] \Count the number of 1's\
B: [count 6 in Q] \Count the number of 6's\


if A = 3 {
result: -30 \Triple 1's, super epic fail\
} else if A = 2 {
result: -25 \Double 1's, epic fail\
} else if B = 3 {
result: 30 \Triple 6's, super epic win\
} else if B = 2 {
result: 25 \Double 6's, epic win\
} else if [triples Q] = 1 {
result: Q + 3 \Triples, 2-5\
} else if [doubles Q] = 1 {
if A = 1 {
result: Q - 1 \Doubles with a 1, no bonus and the 1 doesn't count\
} else if B = 1 {
result: Q + 3 \Doubles with a 6, plus 3!\
} else {
result: Q + 1 \Doubles, plus 1\
}
} else {
if A = 1 {
result: Q - 1 \Ones don't count towards the total\
} else if B = 1 {
result: Q + 2 \Sixes add 2 to the total\
} else {
result: Q \Everything else, just sum the result\
}
}
}

obryn
2015-01-13, 04:20 PM
Updated AnyDice (http://anydice.com/program/5084)
My eyes are bleeding. Every design sensibility in my body is screaming.

OH GOD I CAN SEE FOREVER

Knaight
2015-01-13, 07:10 PM
My eyes are bleeding. Every design sensibility in my body is screaming.

OH GOD I CAN SEE FOREVER

You're not the only one. This is generally a pretty contentious forum when it comes to the quality of just about any design, universal disapproval like this is rare. It's also telling.

Almarck
2015-01-13, 07:15 PM
Wasn't there a mechanic in one of the 3.5 DM books that proposed a similar mechanic?

The mechanic is pretty redundant, since it tries to accomplsih what a d20 does, but with more dice rolls, and even then it does a worse job at it.

What could possibly be done to make this thing less convoluted?

ewoods
2015-01-13, 07:28 PM
What could possibly be done to make this thing less convoluted?

I think we first have to define very clearly the problem that it's trying to solve.

Hiro Protagonest
2015-01-13, 07:50 PM
So... when you roll three 1s, the entire party dies in your epic failure and it unintentionally ends up being the conditions to summon Orcus, while if you roll three 6s, you kill the BBEG in one shot (doesn't matter where he is, your attack defies the laws of space and interdimensional travel) and impress an angel so much she becomes your girlfriend?

Actually, I don't think those are the absolute best or worst things possible...

Hytheter
2015-01-13, 08:07 PM
There's no remaining 1. 1 and 6 cancel to give 5 leaving 5 and 6 which total to 11. Have to assume you meant 6 1 1 in which case on a re-read you're right.

Oh yes I did mean that, whoopsie.


Updated AnyDice (http://anydice.com/program/5084)

Yeah that looks pretty much exactly like the graph I made earlier, so we're definitely on the same page. And it's an ugly page. It probably should be removed from the book.

I followed the site back to the guy's twitter. When he posts a link to un-twenty there he says "free of charge!" as though it's something worth paying for...

Knaight
2015-01-13, 08:34 PM
So... when you roll three 1s, the entire party dies in your epic failure and it unintentionally ends up being the conditions to summon Orcus, while if you roll three 6s, you kill the BBEG in one shot (doesn't matter where he is, your attack defies the laws of space and interdimensional travel) and impress an angel so much she becomes your girlfriend?

Actually, I don't think those are the absolute best or worst things possible...

Presumably, it's supposed to be in the context of what's being done. That's the sad part about this - the idea of dice imparting an effect beyond the raw total is cool, it's just the single worst implementation I've ever seen. You've got a sufficiently rare extreme failure and success, you've got a mechanic that was used for auto success and failure that would work well for complications and benefits, an then there's just all that other crap on top of it.

Ravens_cry
2015-01-13, 09:10 PM
The Ghost die in ye olde Ghostbusters RPG (I bought a copy at a second hand store) did that. If the ghost symbol came up when the baddies rolled, it meant something extra good for the baddies, while if it came up when the players rolled, it meant something bad for the players above and beyond what was rolled on the die. It was a very rules light system, the character sheets fit on an index card with room for a small head shot, so on the fly ruling were a big part of the game anyway.

Knaight
2015-01-14, 12:27 AM
The Ghost die in ye olde Ghostbusters RPG (I bought a copy at a second hand store) did that. If the ghost symbol came up when the baddies rolled, it meant something extra good for the baddies, while if it came up when the players rolled, it meant something bad for the players above and beyond what was rolled on the die. It was a very rules light system, the character sheets fit on an index card with room for a small head shot, so on the fly ruling were a big part of the game anyway.

There are a lot of systems that use something similar, which range from pretty rules light to pretty rules heavy (e.g. Shadowrun). In short, there are a lot of working, well designed implementations that the Un-Twenty designer could have used as inspiration, and clearly didn't.

Solaris
2015-01-14, 09:01 AM
Wasn't there a mechanic in one of the 3.5 DM books that proposed a similar mechanic?

Yes (http://www.d20srd.org/srd/variant/adventuring/bellCurveRolls.htm), although I'm given to understand that it's less of an abomination than this and actually evens out the bell curve.
I like swingy - but this is unnecessarily convoluted, complex, ill-defined, and outright stupid.

Segev
2015-01-14, 09:33 AM
I'm with the people asking what problem this is trying to solve.

If it's just that he likes the bell curve, I again recommend 3d6 + 2d(+/-). For clarity, that's 3 normal 3d6, summed, and 2 dice which have an even chance of being a +1 or a -1. Called "fudge dice," these can result, together, in a sum of -2, -1, 0, 1, or 2, and thus can allow any value, when added to the 3d6, between 1 and 20 (just like a d20).

However, the probability curve looks like this. (http://anydice.com/program/505e)

Feddlefew
2015-01-14, 09:43 AM
I'm with the people asking what problem this is trying to solve.

If it's just that he likes the bell curve, I again recommend 3d6 + 2d(+/-). For clarity, that's 3 normal 3d6, summed, and 2 dice which have an even chance of being a +1 or a -1. Called "fudge dice," these can result, together, in a sum of -2, -1, 0, 1, or 2, and thus can allow any value, when added to the 3d6, between 1 and 20 (just like a d20).

However, the probability curve looks like this. (http://anydice.com/program/505e)

So two coin flips and 3d6?

goto124
2015-01-14, 09:47 AM
So two coin flips and 3d6?

The coin lands on its edge!

Segev
2015-01-14, 09:50 AM
So two coin flips and 3d6?

That'd one way to do it. I'd recommend two dice of your choice, roll even for +1 and odd for -1, instead, as flipping coins while rolling dice is a bit clunky. Literally; the coins would make clunkish ringing noises that would get tiresome, I expect.

There also exist actual "fudge dice," which are cubes with "+" on three sides and "-" on the other 3.

But as long as you have a typical gamer's set of dice, 3d6 plus 2d(anything else), using evens/odds for +/- 1 on the non-d6s, should be easy enough. Certainly easy enough for any group willing to use the system proposed at the start of this thread.

Broken Twin
2015-01-14, 09:57 AM
Huh, I never considered using FUDGE dice to bump the 3d6 range back into 1-20. Now I really do need to pick some up.

As an aside, has anyone considered/actually used d8+d12 for their 1-20 roll? It's a very flat bell curve, which could be either a good thing or not, depending on what you're looking for. Looks like it would work well as a middle ground between the randomness of d20 and the consistent curve of 3d6.

Segev
2015-01-14, 10:19 AM
As an aside, has anyone considered/actually used d8+d12 for their 1-20 roll? It's a very flat bell curve, which could be either a good thing or not, depending on what you're looking for. Looks like it would work well as a middle ground between the randomness of d20 and the consistent curve of 3d6.

It retains the problem that it's only 2-20. You could adjust that with a Fudge die, and just treat + as "+0" while - is still "-1," though. (They're really useful for, ahem, fudging one combination of dice's range.)

Even with the ranges restored to 1-20, however, you have to be careful in analyzing the DCs. d20 really is designed with probability-to-succeed being based on the flat "curve" of a single die. Bonuses and penalties mean increasingly more the further apart they push values with a bell curve. (They only mean a non-linear difference with a d20 if they push the difference over 20, at which point they push it from linear to "impossible.")

On the other hand, the more bell-like your curve, the closer to the statistical mode is the choice to "take 10." It's a little under average (10.5 on a d20), but the standard deviation on a flat curve is such that the mode is actually not really a valid thing to examine.

Put the bell curve in place for, say, the 3d6+2d(+/-), though, and your mode becomes either 10 or 11. Which is right there around the average, and which means "taking 10" is going to generate one of the two most likely solutions.

d8+d20 will have 9-13 as the shared mode. Taking 10 is thus still closer to the mode than it is in a d20, but the variance is flat around it, even so. (Technically, the average of the modes is 11 on d8+d12, because of the loss of 1 from the range.)

So, do you like having a flat range in your probability? Do you want it smaller than the whole of the range, with the ends tapering off? If so, d8+d12 will be pretty good for you. But it is an interesting question: why do you want a flat portion of it with tapering edges, rather than a bell curve or just a flat probability?

Firest Kathon
2015-01-14, 10:23 AM
I'm with the people asking what problem this is trying to solve.

If it's just that he likes the bell curve, I again recommend 3d6 + 2d(+/-). For clarity, that's 3 normal 3d6, summed, and 2 dice which have an even chance of being a +1 or a -1. Called "fudge dice," these can result, together, in a sum of -2, -1, 0, 1, or 2, and thus can allow any value, when added to the 3d6, between 1 and 20 (just like a d20).

However, the probability curve looks like this. (http://anydice.com/program/505e)

Fudge dice, at least the ones I own, have two sides blank, two sides with -, and two sides with +. So while the possible results are the same, the distribution looks slightly different. In this system, it makes 1 and 20 even less likely (0.05% each).

Corrected Anydice (http://anydice.com/program/509b)

Segev
2015-01-14, 10:27 AM
Fudge dice, at least the ones I own, have two sides blank, two sides with -, and two sides with +. So while the possible results are the same, the distribution looks slightly different. In this system, it makes 1 and 20 even less likely (0.05% each).

Corrected Anydice (http://anydice.com/program/509b)

Ah, my mistake. I don't own any, myself.

I would recommend using modified ones that lack the blanks, then, to avoid pushing the 1 and 20 even rarer, though it's not required.

Feddlefew
2015-01-14, 10:36 AM
Ah, my mistake. I don't own any, myself.

I would recommend using modified ones that lack the blanks, then, to avoid pushing the 1 and 20 even rarer, though it's not required.

To get a +/- 1 on a pair of fudge dice, there has to be a 0 side. Otherwise the only combinations are +2, 0, and -2.

Edit: You could use a regular d6, with 1 and 2 being -, 3 and 4 being 0, and 5 and 6 being +.

Segev
2015-01-14, 10:52 AM
To get a +/- 1 on a pair of fudge dice, there has to be a 0 side. Otherwise the only combinations are +2, 0, and -2.

Edit: You could use a regular d6, with 1 and 2 being -, 3 and 4 being 0, and 5 and 6 being +.

Hm, true. Still works for 1-20 with a bell curve. The question really is just how rare you want the 1 and the 20. With true fudge dice, they're half as likely as with the variant I initially proposed. The variant I initially proposed flattens the whole curve just a little, most notably at the tails.

So again, it's a matter of just how rare you want the outliers to be.

Altair_the_Vexed
2015-01-14, 10:56 AM
It is overly convoluted.
It adds complexity without clarity.
Its effects are not clearly understood.
It is intended to solve a problem that is not well defined.

Gygax would have loved it.
I'm putting that in my sig.

ewoods
2015-01-14, 11:29 AM
What would be the purpose of a more bell-shaped distribution though? If the designer just wants more rolls closer to 10, why not simply modify the existing take-10 mechanic? Houserule that you can take 10 on any d20 check but if you want something higher than that, you have to actually roll and risk getting something lower as well.

AstralFire
2015-01-14, 11:34 AM
What would be the purpose of a more bell-shaped distribution though?

To get more consistent results without perfectly consistent results? Seems kind of self-evident to me. My problem is that of the systems that use d20 inherently, it tends to break them (especially 4E and 5E D&D. 3E's already broken in other ways so you don't notice it so much.)

ewoods
2015-01-14, 11:52 AM
To get more consistent results without perfectly consistent results?

Why is that something that's needed though? Is there something wrong with having an equal chance to get any number on any given d20 roll? Maybe it's just something I've never put a lot of thought into.

AstralFire
2015-01-14, 12:30 PM
Why is that something that's needed though? Is there something wrong with having an equal chance to get any number on any given d20 roll? Maybe it's just something I've never put a lot of thought into.

Jump results generally have a 1:1 relationship between the total result and feet jumped. This means that a veteran jumper with a +5 on his roll can -- on luck of the draw -- have an equal chance of jumping 6 feet or 25 feet. This is an extremely large variance to have occur on a regular basis.

2E, 5E and 4E don't need bell curve rolls as much for various reasons, but 3E ends up with some really ridiculous results for some things you can use a d20 for.

ewoods
2015-01-14, 12:50 PM
I guess that just makes sense to me though. I've never thought of the dice rolls as being part of the character's skill. If you have 5 ranks in jump, your skill in jumping is 5. It's not 5 plus whatever you roll on the die. The die roll represents all of the variables that go into that jump beyond the character's skill. It's the consistency of the ground, the way he planted his feet, wind speed and direction, adrenaline, concentration, etc. If he manages to jump 25 feet it's not because he's really good at jumping, it's because he got exceptionally lucky, and he shouldn't expect to get that lucky every single time. He should expect that he can jump at least 6 feet under the worst of circumstances (which is 5 feet further than a character who has no ranks in jump), and over 100 jumps he'll probably jump an average of 15 feet. As a DM, I believe it's my job to take out-of-game information, such as dice rolls to jumping, and translate it into in-game information. So if he happens to roll a 1 this time and only make it six feet, you don't just say, "Ok, you only jump six feet." You say, "At the moment when you're about to jump, the ground beneath your feet gives way slightly and you awkwardly hurdle sideways through the air, flailing your arms as you manage to land a mere six feet away." A character with no ranks to jump who rolls a 1 just falls flat on his face or merely trips and stumbles forward.

Broken Twin
2015-01-14, 12:56 PM
It retains the problem that it's only 2-20. You could adjust that with a Fudge die, and just treat + as "+0" while - is still "-1," though. (They're really useful for, ahem, fudging one combination of dice's range.)

Even with the ranges restored to 1-20, however, you have to be careful in analyzing the DCs. d20 really is designed with probability-to-succeed being based on the flat "curve" of a single die. Bonuses and penalties mean increasingly more the further apart they push values with a bell curve. (They only mean a non-linear difference with a d20 if they push the difference over 20, at which point they push it from linear to "impossible.")

On the other hand, the more bell-like your curve, the closer to the statistical mode is the choice to "take 10." It's a little under average (10.5 on a d20), but the standard deviation on a flat curve is such that the mode is actually not really a valid thing to examine.

Put the bell curve in place for, say, the 3d6+2d(+/-), though, and your mode becomes either 10 or 11. Which is right there around the average, and which means "taking 10" is going to generate one of the two most likely solutions.

d8+d20 will have 9-13 as the shared mode. Taking 10 is thus still closer to the mode than it is in a d20, but the variance is flat around it, even so. (Technically, the average of the modes is 11 on d8+d12, because of the loss of 1 from the range.)

So, do you like having a flat range in your probability? Do you want it smaller than the whole of the range, with the ends tapering off? If so, d8+d12 will be pretty good for you. But it is an interesting question: why do you want a flat portion of it with tapering edges, rather than a bell curve or just a flat probability?

I like it because, while it may not be a bell curve in the strictest sense, it's the flattest 'curve' you can get while staying simple enough for the players. I like the normalization of results that a bell curve offers, but I also like the chances for extraordinary results that a linear system offers. A compromise between the complete randomness of d20 and the relative predictability of 3d6 is nice for me. I like that its average is slightly higher than taking ten, as it means that you're taking a risk by rolling for an on-average slightly better result. And its shallower "curve" screws with the math of d20 systems less. I tried switching to 3d6 in 3.5, but the shear amount of rebalancing that would need to be done to account for the change in probabilities made it completely not worth it. With a more balanced system (5E) that has less number inflation, plus a shallower curve, I think I could get away with little if any rules modification.

Plus, when it comes down to it, my players would much rather roll two dice then three/five.

Edit: Although, now that I think about it, 5E handles things fairly well with the Adv/Dis mechanic, so I'm not sure I'd really even want to introduce it into the game. Mostly because I tend to cap out my players' willingness to roll dice for one thing to three.

AstralFire
2015-01-14, 01:00 PM
I guess that just makes sense to me though. I've never thought of the dice rolls as being part of the character's skill. If you have 5 ranks in jump, your skill in jumping is 5. It's not 5 plus whatever you roll on the die. The die roll represents all of the variables that go into that jump beyond the character's skill. It's the consistency of the ground, the way he planted his feet, wind speed and direction, adrenaline, concentration, etc. If he manages to jump 25 feet it's not because he's really good at jumping, it's because he got exceptionally lucky, and he shouldn't expect to get that lucky every single time. He should expect that he can jump at least 6 feet under the worst of circumstances (which is 5 feet further than a character who has no ranks in jump), and over 100 jumps he'll probably jump an average of 15 feet. As a DM, I believe it's my job to take out-of-game information, such as dice rolls to jumping, and translate it into in-game information. So if he happens to roll a 1 this time and only make it six feet, you don't just say, "Ok, you only jump six feet." You say, "At the moment when you're about to jump, the ground beneath your feet gives way slightly and you awkwardly hurdle sideways through the air, flailing your arms as you manage to land a mere six feet away." A character with no ranks to jump who rolls a 1 just falls flat on his face or merely trips and stumbles forward.

And that's a fine approach -- though I'd say you're adjusting the rules yourself, there, because another skill should be invoked to handle slippery terrain. For me, however, I found that sort of thing frequently awkward in 3E D&D when it occurred on a regular basis. The ground can only shift under you so many times before some people get frustrated with their character being confounded by odd luck and consistent wide variance. I generally found it easiest to replace skill rolls with a bell curve; it made the natural 3s and natural 18s much more meaningful.

I don't do it in 5E because of the dis/advantage mechanic, though, which works well enough to represent situations which should have a tighter box of results.

Jay R
2015-01-14, 01:09 PM
It's worth noting that if you replace a combat roll in D&D 3E or 3.5E with a more bell-shaped curve, you reduce the chance for critical hits tremendously, and greatly reduce the value of magic items that have powerful critical hits.

Segev
2015-01-14, 02:03 PM
I actually do like the RP approach to explaining the results of a die roll being poor as external factors getting in your way. It doesn't always work, but it's a nice way to make it less "ha ha your character is a joke at what he's supposed to be skilled at" than things can otherwise go.

As for flat vs curved probabilities, it is largely a matter of taste, overall. But d20 is designed for a flat curve, so it's something to keep in mind. For instace, a "20" on a d20 happens 5% of the time. That translates to a roll of ~17+ on the 3d6+2dFudge method. A "19-20" would translate to a 16+. It would be difficult to GET the same probability as an 18-20, because 15+ actually jumps to the same odds as 17-20.

So there are oddities to look out for.

...actually, while it wouldn't be exact, I just ran some test numbers. If you roll 3d6, the odds of two of them matching and coming up "6" are 5.55(repeating)%. This is pretty close to the 5% odds of a "nat 20" on a d20. Turns out that the chance of matched 5s or matched 6s is 11.11(repeating)%. That's a little higher than the 10% chance of a "nat 19 or 20." Even "matched 4s, 5s, or 6s" translates to a 16.66666% chance. Again, 1.6(repeating) higher than the 15% that an 18-20 on a d20 would represent.

Also a 22.22(repeating)% chance of matched 3s, 4s, 5s, or 6s (matching nicely to the 20% chance of a 17-20). We're even staying marginally close at 27.77(repeating)% chance that matched dice of at least value 2 will appear (compared to 25% chance that a 16-20 will show up).

If all we require is two matched values on 3d6, that's a 1/3 (33.33(repeating)%) chance. We're definitely higher, now, than the 30% chance of a 15-20 on a d20, but honestly, how many crit ranges get that big?



All of this to say: You can use the 3d6+2dFudge approach and keep the value of weapons which do cool things on critical hits roughly the same (maybe even a little increased) by having, instead of "nat 20," the critical threat check be "did you get matched 6s?"

If your crit threat range increases, then you add more allowed values for the match.

If your threat is on a nat 20, then the new threat is on 2 matched 6s.
If your threat is on a 19-20, then the new threat is on 2 matched 5s OR 6s.
If your threat is on an 18-20, then the new threat is on 2 matched 4s, 5s, or 6s.
If your threat is on a 17-20, then the new threat is on 2 matched 3s (or higher).
If your threat is on a 16-20, then the new threat is on 2 matched 2s (or higher).
If your threat is on a 15-20, then the new threat is on any matched pair.

No extra rolling beyond what you were already doing, slightly (roughly 2%) higher chances of crit threats. Plays with fun qualities people tend to like looking for in dice anyway.

AstralFire
2015-01-14, 02:06 PM
It's worth noting that if you replace a combat roll in D&D 3E or 3.5E with a more bell-shaped curve, you reduce the chance for critical hits tremendously, and greatly reduce the value of magic items that have powerful critical hits.

The UA rule that discusses 3d6 die includes equivalents for the new threat ranges (http://www.d20srd.org/srd/variant/adventuring/bellCurveRolls.htm), though I personally find them a bit messy. It would probably better to up the power of a critical hit a bit and just allow crit stacking to be geometrically better rather than linearly, in terms of speed of play. Crits are generally weak in 3.x past the lowest levels anyway.

Segev
2015-01-14, 02:08 PM
The UA rule that discusses 3d6 die includes equivalents for the new threat ranges (http://www.d20srd.org/srd/variant/adventuring/bellCurveRolls.htm), though I personally find them a bit messy. It would probably better to up the power of a critical hit a bit and just allow crit stacking to be geometrically better rather than linearly, in terms of speed of play. Crits are generally weak in 3.x past the lowest levels anyway.

You don't want to stack them faster; that only makes those who take the threat-range increases even more egregious. Matching dice actually turns out to be rather close to the same probabilities, though.

AstralFire
2015-01-14, 02:12 PM
You don't want to stack them faster; that only makes those who take the threat-range increases even more egregious. Matching dice actually turns out to be rather close to the same probabilities, though.

Was my point. Crits kind of suck in 3.x, generally speaking. I could easily imagine an overhaul for TWF that was based around bell curve rolls and crit stacking.

...

How much does it say about me that my first inclination when involving any 3.x houserules is that it's acceptable that you'll have to houserule seven other things to get the first one working?

Segev
2015-01-14, 02:15 PM
How much does it say about me that my first inclination when involving any 3.x houserules is that it's acceptable that you'll have to houserule seven other things to get the first one working?

I think it says you've experience with the law of unintended consequences and how ANY system will tend to have enough interlocked moving parts that you'll need to watch for at least the biggest side-effects of any given change.

The Grue
2015-01-14, 03:27 PM
The coin lands on its edge!

I can't find a suitable screen capture so just imagine I posted Kain's terrifying smile here.

Knaight
2015-01-14, 03:55 PM
That'd one way to do it. I'd recommend two dice of your choice, roll even for +1 and odd for -1, instead, as flipping coins while rolling dice is a bit clunky. Literally; the coins would make clunkish ringing noises that would get tiresome, I expect.

There also exist actual "fudge dice," which are cubes with "+" on three sides and "-" on the other 3.


As has been stated, two sides are blank. There's also a variant set of fudge dice where you have four blank sides, one plus, and one minus, though I'm not aware of any commercial manufacture of them. They're also generally sold in sets of 4, 12, or 20, so just getting the physical dice is pretty useful, and you'll get more than enough to use a 3d6+2dF system. Granted, I might be overvaluing them as I mostly play Fudge.

obryn
2015-01-14, 04:26 PM
It's worth noting that if you replace a combat roll in D&D 3E or 3.5E with a more bell-shaped curve, you reduce the chance for critical hits tremendously, and greatly reduce the value of magic items that have powerful critical hits.
It largely depends on how you do it. Obviously, you can't leave the range unadjusted without side-effects in any d20 system.

If you're using 2d10, you can still use dice-counting tricks, here. For example, you have a white die and a red die.

On a 20-crit, you need the red die to be 0 and the white to be 6-0
On a 19-crit, you need the red die to be 0
On an 18-crit, you need the red die to be 0, or the red die to be 9 and the white die 6-0
On a 17-crit, you need the red die to be 9 or 0.

And so on. There's an interaction with the roll needed to-hit, here, but I'm confident that's a solvable issue.

MKV
2015-01-14, 04:57 PM
If it's just that he likes the bell curve, I again recommend 3d6 + 2d(+/-). For clarity, that's 3 normal 3d6, summed, and 2 dice which have an even chance of being a +1 or a -1. Called "fudge dice," these can result, together, in a sum of -2, -1, 0, 1, or 2, and thus can allow any value, when added to the 3d6, between 1 and 20 (just like a d20).

I have always been firmly of the opinion that rolling fewer dice is better than rolling more dice in almost every situation. Sure it's fun to pick up every d6 on the table to roll the damage for fire ball but if I had to roll 5 dice every time I wanted to roll an attack or skill check I would go stark raving mad over the course of a single session. While I can see the benefit of a bell curve it does not outweigh the fact that if I wanted to implement this system I would have to buy enough fudge dice for everyone in my group and always have five dice on hand rather than one. And if I wanted to roll multiple attacks:smalleek:. I may have over 100 dice but I would much prefer to play a game that uses 7 of them rather than all of them.

Segev
2015-01-14, 05:02 PM
I should note that I prefer to just use a d20, myself. The suggestions in this thread are in response to the OP, which outlines a complex system. Presumably, anybody using such a system is not opposed to the complexity of extra dice.