D&D General A d12 (not d20) D&D System?

DND_Reborn

Legend
Anyone know if, instead of d20, some one has made a d12 D&D system?

I've tried searching, but everything is about how or when d12 is used in D&D. I've also found some 2d6 systems, but not d12.
 

log in or register to remove this ad


NotAYakk

Legend
A d12 has a variance of 143/12. A d20 399/12, and 3d6 a variance of 105/12.

So in a roll over/under system, 3d6 modifiers away from average are "twice as large" as d20, and d12 are 1.7x as large as d20. (how big modifiers are scales with standard deviation, the square root of variance).

Ie, a system with DCs scaled 40% towards 10, then being 4 lower and modifiers 40% smaller would feel about the same. Attributes from -3 to +3, proficiency from +2 to +4, naked being 6 AC and plate+shield being 12 AC.

We can add +4 to the system by making attributes range from +1 to +7 (no minuses) with +4 being average human. Set proficiency to +2 to +4. DCs are 4+prof+attribute. unarmored is 6+dex, light armor is 7+dex, medium is 11+dex/2 (+1 if bulky), and heavy is 15. Shields grant +1 AC. Magic items cap out at +2 instead of +3. Etc.

...

The interesting thing happens when you add not roll over/under mechanics. Up to that, we just get modifier tweaks. While muliple dice are "curvier", when you reduce it to roll under/over and scale by the SD, the only substantial difference happens in the top/bottom 5%ish (the crit hit/miss territory). Integration makes things smoother, and "roll under/over" is integration of probability.
 
Last edited:



Jaeger

That someone better
A d12 has a variance of 143/12. A d20 399/12, and 3d6 a variance of 105/12.

So in a roll over/under system, 3d6 modifiers away from average are "twice as large" as d20, and d12 are 1.7x as large as d20. (how big modifiers are scales with standard deviation, the square root of variance).

Ie, a system with DCs scaled 40% towards 10, then being 4 lower and modifiers 40% smaller would feel about the same. Attributes from -3 to +3, proficiency from +2 to +4, naked being 6 AC and plate+shield being 12 AC.

We can add +4 to the system by making attributes range from +1 to +7 (no minuses) with +4 being average human. Set proficiency to +2 to +4. DCs are 4+prof+attribute. unarmored is 6+dex, light armor is 7+dex, medium is 11+dex/2 (+1 if bulky), and heavy is 15. Shields grant +1 AC. Magic items cap out at +2 instead of +3. Etc.

...

How would this scale if the d12 explodes on a 12, similar to the d10 dice mechanic in CP RED and the Witcher RPG?

I ask because my mathematic ability is horrible, I got lost at: "scales with standard deviation, the square root of variance"...LOL.
 

dave2008

Legend
A d12 has a variance of 143/12. A d20 399/12, and 3d6 a variance of 105/12.

So in a roll over/under system, 3d6 modifiers away from average are "twice as large" as d20, and d12 are 1.7x as large as d20. (how big modifiers are scales with standard deviation, the square root of variance).

Ie, a system with DCs scaled 40% towards 10, then being 4 lower and modifiers 40% smaller would feel about the same. Attributes from -3 to +3, proficiency from +2 to +4, naked being 6 AC and plate+shield being 12 AC.

We can add +4 to the system by making attributes range from +1 to +7 (no minuses) with +4 being average human. Set proficiency to +2 to +4. DCs are 4+prof+attribute. unarmored is 6+dex, light armor is 7+dex, medium is 11+dex/2 (+1 if bulky), and heavy is 15. Shields grant +1 AC. Magic items cap out at +2 instead of +3. Etc.
So what is the point of revising how or what you roll and then changing all the modifiers to give you a similar experience? Isn't the point to change the experience?
 

DND_Reborn

Legend
UPDATE:

So, the reason I asked about this was two-fold.

1. To see if it was already out there.
2. Because I am going to make d20 5E into d12 since I find the d20 too broad and swingy. The modifiers are too small for the die size.

FWIW, I am not adjusting ACs or DCs (in general), although what DCs correspond to what task difficulties will be adjusted because the DCs as they are seem sort of silly (DC 5 for a VERY EASY task? Really??).

This will, of course, make a very big difference in the experience--which is what I am seeking. Instead of hitting 65%, for example, it will be closer to 42%. Saving throws will be harder, creating greater impact. I am still keeping the reduced HP I've been doing for a while now, since the bloat won't be needed either.

We shall see how it goes. It might work as I hope, or it might fail completely. Either way, it should be interesting. :D
 

GMMichael

Guide of Modos
2. Because I am going to make d20 5E into d12 since I find the d20 too broad and swingy. The modifiers are too small for the die size.
There's an old game. I want to say it was called...3rd edition?...that used larger modifiers to keep the d20 happy.
(DC 5 for a VERY EASY task? Really??).
Well, no. There is no roll for very easy tasks. Unless something interesting happens, like the skies rain fire. Then a "very easy" task gets a little more interesting, and the DM can call for a roll.
We shall see how it goes. It might work as I hope, or it might fail completely. Either way, it should be interesting. :D
I'm pretty sure swapping a d12 for a d20 will solve most of the issues with 5e: players forgetting their Bonds, DMs forgetting to give Inspiration, the whole out-of-sight-but-not-hidden thing. It's great for Bounded Accuracy too - a d12 will keep the numbers lower.

Or you'll get a bunch of confused and angry players, thusly resulting in less free pizza. It's a risk I wouldn't take.
 

Jaeger

That someone better
So what is the point of revising how or what you roll and then changing all the modifiers to give you a similar experience? Isn't the point to change the experience?

It's an interesting thought exercise. No harm in that.

One reason I'm interested in a d12 variant is the D&D systems that were dropped with 3e: Reaction, & Morale rules were 2d6 based.

It should be easy to move those to 1d12 rolls for a true 'universal' system.

Unneeded in the hobby, but seeing as how I homebrew for most games I run now - I'm more into interesting variants for my gaming group.


Because I am going to make d20 5E into d12 since I find the d20 too broad and swingy. The modifiers are too small for the die size.

d16's are more or less readily available - it might be a worth looking into...


FWIW, I am not adjusting ACs or DCs (in general), although what DCs correspond to what task difficulties will be adjusted because the DCs as they are seem sort of silly (DC 5 for a VERY EASY task? Really??).

Kinda why I'm interested in an exploding 12 variant, I'd like to know the math for that before I'd consider using it as a mechanic.


his will, of course, make a very big difference in the experience

I tend to agree. Sometimes changes don't seem like that big of a deal, but during actual play you see the PC's making very different in game decisions.

players forgetting their Bonds, DMs forgetting to give Inspiration, the whole out-of-sight-but-not-hidden thing.

In my opinion: The first two are virtually vestigial systems - Ideas that are half-baked, and thus poorly implemented in the rules. If they were actually better integrated and more meaningful, people wouldn't forget as much... And sometimes a piece of bad game design is just a piece of bad game design.

Don't get me started on "passive" checks...
 

DND_Reborn

Legend
There's an old game. I want to say it was called...3rd edition?...that used larger modifiers to keep the d20 happy.
Tried 3E back in 2005 (or 2007??? I can't recall) and was more impressed with d20 SW based on the same (mostly) mechanics. I found it worked well for SW, but not so much for D&D. I still have a couple books and if this d12 thing doesn't work maybe I'll dig out 3E...

Well, no. There is no roll for very easy tasks. Unless something interesting happens, like the skies rain fire. Then a "very easy" task gets a little more interesting, and the DM can call for a roll.
Well, there are though, since the game includes a DC for Very Easy tasks after all. They aren't used often, but that just begs they point why have them?

I'm pretty sure swapping a d12 for a d20 will solve most of the issues with 5e: players forgetting their Bonds, DMs forgetting to give Inspiration, the whole out-of-sight-but-not-hidden thing. It's great for Bounded Accuracy too - a d12 will keep the numbers lower.
I am hoping so. :)

Or you'll get a bunch of confused and angry players, thusly resulting in less free pizza. It's a risk I wouldn't take.
LOL, true, but with my diet I am cutting out pizza anyway. ;) And frankly, I am getting tired of it...
 

DND_Reborn

Legend
d16's are more or less readily available - it might be a worth looking into...
I actually tried 2d8's, but for once I actually think the linear distribution is better. So, I also thought about generated 1-16 using a d6 and d8:

d6 = 1-3 means +0, 4-6 means +8
d8 generates the rest.

But, I am not a fan of such systems in general....

Kinda why I'm interested in an exploding 12 variant, I'd like to know the math for that before I'd consider using it as a mechanic.
It works, but you end up with two "tiers" of results, the 1-11, and then the much less common 13-24. It also makes a result of 12 impossible unless the exploding roll is d12-1 (for +0 to +11). It is easier IMO just to do a roll of 12 always succeeds.

I also tried 2d6, allowing 6's to explode once, for a result of 2-24. This works very well really when you look at the math behind it, and I might go this route if the d12 doesn't work. With this method, you can still get a 12 (for example, roll a 5, 6, and then a 1 on the exploding roll).

Either method will allow rolls above 12, so will work if the d12 capped at 12 is too big of an adjustment.
 


DND_Reborn

Legend
Well, you can also do the opposite. Keep the d20 and scale the modifiers.

The point is that roll under/over with dice change only makes modifiers different in size.
Yeah. I am hoping changing the die will be easier. I've tried changing all the modifiers, but it affects virtually everything and is a lot of adjustments. As where going to a smaller die will hopefully have similar impact but with much less work.
 

dave2008

Legend
Well, you can also do the opposite. Keep the d20 and scale the modifiers.

The point is that roll under/over with dice change only makes modifiers different in size.
Yes, isn't that one of the features of going to the d12? The OP even said do, though in an update pot:

UPDATE:

So, the reason I asked about this was two-fold.

1. To see if it was already out there.
2. Because I am going to make d20 5E into d12 since I find the d20 too broad and swingy. The modifiers are too small for the die size.
 

dave2008

Legend
Yeah. I am hoping changing the die will be easier. I've tried changing all the modifiers, but it affects virtually everything and is a lot of adjustments. As where going to a smaller die will hopefully have similar impact but with much less work.
Is there a particular reason you are not looking at 2d6? Or even 3d6? Both are less swingy.

PS I have also though of doing something like this, so I would love to hear how it foes for.
 

DND_Reborn

Legend
Is there a particular reason you are not looking at 2d6? Or even 3d6? Both are less swingy.
Actually I looked at both, even 3d6-2 (for a range of 1-16). And 3d6 is too large maximum at 18, practically 20 from a d20...

Less swingy is actually a bad thing when you get into smaller ranges. It means a single point has more impact.

For example, with d12, if you need a 10 you have a 25% of success. Getting a +2 increases that to 41.7% (a significant increase, 16.7%).
Now, do the same numbers with 2d6. A 10 or better is just 16.7%, but the +2 increase jumps it up to 41.7% (a larger increase of 25%!).

So, a less swinging method causes greater increases. Also with a smaller die I don't want the extremes to be too unlikely, and for that a linear distribution works better IMO. With 2d6 a 12 (the maximum) is only 2.8%, but with d12 it is 8.3%.
 

GMMichael

Guide of Modos
Less swingy is actually a bad thing when you get into smaller ranges. It means a single point has more impact.
You know, I wrote two(ish) rules into Modos 2 that completely eliminate the Swingy Problem. As long as you're writing/homebrewing, you should check them out. Here's the jist:

Rule 003: If a player rolls higher than the GM, he/she gets a favorable outcome. Lower is unfavorable, and a tie is up to the GM. (This leaves room for interpretation, unlike succeed/fail rules.)

Rule 012: A player can choose to take half of the highest result on a die instead of rolling for the result. (The GM can then roll against, or simply adjudicate based on the result.)

 

Jaeger

That someone better
It works, but you end up with two "tiers" of results, the 1-11, and then the much less common 13-24. It also makes a result of 12 impossible unless the exploding roll is d12-1 (for +0 to +11). It is easier IMO just to do a roll of 12 always succeeds.

Yes, 12-13 will be the same number...

R.tal has used this with d10's since CP2020.

Yet I've never seen the math breakdown even from them of the exploding d10 or d12 stat+skill vs. a variety of TN's.

If someone knows of one I'd like to see it.



I actually tried 2d8's, but for once I actually think the linear distribution is better. So, I also thought about generated 1-16 using a d6 and d8:

Tried a straight-up d16 like this?

dado-d16-azul-600x600.jpg


You'd have to change how crits work: maybe +10 over DC like PF2 does.
 

DND_Reborn

Legend
Yet I've never seen the math breakdown even from them of the exploding d10 or d12 stat+skill vs. a variety of TN's.

If someone knows of one I'd like to see it.

Click on the Data: At Least (shown below) to see the % to hit different TNs.

1654036913510.png


Tried a straight-up d16 like this?

dado-d16-azul-600x600.jpg


You'd have to change how crits work: maybe +10 over DC like PF2 does.
Well, first I don't want to buy dice just to try something when I can do the 1d6 (1-3 on d6 adds nothing, 4-6 adds +8) and 1d8 to get the same results.

Also, we have been doing critical damage (not attacks) for several months now and will never go back. Each new player that has joined us loves it and agrees it is definitely better than critical "hits". So, I don't have to worry about that with the d12 or d16 or whatever we end up using. :)
 

Level Up!

An Advertisement

Advertisement4

Top