Variant Stress Die

There are many things I like about Ars Magica. One I don't is simple vs. Stress die. With a simple die, the result is 1-10, with a 1 being the worst result, and a 0 being the best (a 10). With a stress die, best and worst are inverted. The result is usually 2-9, with 1 being (possibly but not always) the best result and 0 (now 0 instead of 10) being the worst.

In my first combat, at a dramatically important moment, a grog acting as vanguard for a group of archers rolled a 1. He was momentarily worried, until he realized this was a stress-die situation, making a 1 a good thing. Then, excited, he rerolled and got a 2. So his final result was only a 4. Not exactly the "critical success" he was expecting.

I prefer that the dice be more consistent. I have proposed to my troupe the following variant, and they have agreed, but I'm curious what more experienced players and storyguides think:

With a stress die, 2-9 are just that. 1 is a potential botch. Roll the botch dice, and if any come up a 1, you have botched. If not, the result is calculated as if you have rolled a 1. 0 is a potential great success. Roll again and double the result. If 0 again, roll again and quadruple, etc. If the final result of this re-roll is less than 10, treat the result as if you rolled 10.

This keeps the stress die on a more or less 1-10 range, while still allowing for the occasional dramatic success or failure. I think this change will make dice slightly more important, but not enough to really worry me. Botches will be just as likely, but a potential botch that does not do so will be slightly less detrimental, and great successes will be slightly better, as they will always be at least 10.


I also don't expect to use simple die much. Stress die "are rolled when a character is under stress, and thus might succeed spectalularly or fail with equal flair." Most of the time, if the action and its outcome has little dramatic impact, storying it is just fine with me.

Sounds good. Keeps the die results more coherent between stress and simple.

Probably why i havenĀ“t really thought about this issue before.

It also keeps consistency WITHIN the stress die. Its darn confusing for newbies that higher numbers are better, but a 1 is a great result. Unless it isn't, because your re-roll is low. Unless your re-roll is a 1, which is really good.

My new-to-Ars players have lots of experience with other D10 systems, where a 0 is a 10, or a break-away success greater than 10. The idea that 0 is sometimes 0 (when rolling the stress die) and sometimes 10 (when rolling a simple die OR when re-rolling after rolling a 1 on a stress die) just seemed to needlessly complicate something that shouldn't be.

And here's a wrinkle to the stress die debate:

It was a contentious discussion, neither side was convinced the other side was right. There is plenty of ambiguity as to when a stress die is called for...

I like it too. Potentially it could be a bit confusing for players used to the RAW, of course.

Under the RAW, something that I have noticed happens quite often is that a player will make a roll where it is a bit ambiguous if it is stress or simple die. Perhaps a Perception + Hunt roll to track something. The problem is that if the die turns up as a "1" or a "0", the troupe then needs to sort of retro-actively decide whether it was a stress or simple die, which makes a big difference to the outcome. It can be very frustrating if you are a player who has just rolled a "1" on what you assumed was a stress die, to be told: "No, that is a simple die; you fail".

I like it. I considered something similar once, but this is superior to my variant. +1.

For new players it makes a lot of sense, and old timers could/should be able to adapt, although the need for the change in an experienced group is probably far less.

I like it, and am tempted to use it.

I think it you are using this rule it will change the spread of potential values achieved, as a stress roll which multiplies up will now always be great.

Perhaps an alternate to this to avoid even more confusion is that a result of 0 is considered good, and the next result is added to 10, rather than doubled with a minimum. A ten is added and the layer rolls again to add. It makes the super success increase in a consistent manner as well, as a 10 always adds to the to next result.

eg. roll 0, then 4 = 14. Or Roll 0, then 0, then 4 = 24.

You might not like it for Aging rolls, though.

Further to the impact of the change in calculating a potential "crit" result, I've mocked up a spreadsheet to see if there is a significant difference across a range of Crit results. Some of this is obvious, but I thought it was interesting.

For Humboldtscott's method:

  • After the first potential "crit roll" (meaning a 10 is rolled), the final result is never higher than the standard Stress Roll result if the next number rolled is 5 or more for single crit rolls. ie. roll 10, then another number.
  • For dual-crit rolls (where the player rolled a 10, then 10, then another number) the difference is far smaller.
  • For three-crit rolls (where the player rolled a 10, 10, 10 then another number) the result is only different if the number rolled is a 1.
  • Makes any "crit" better than a standard result, but not any different to normal stress rolls at the extremely low probability.

For my suggested method:

  • The method scales in a linear way, where it is not possible to gain a good result. Suits games where rare exceptional results are not wanted, but crits consistently perform better.
  • the degree of variation for very rare circumstances (10,10,10, + normal roll) is very significant; being both drastically higher is the number rolled is low (compare 8 vs 31), and far lower than standard if the number rolled is high (72 vs 39).

My conclusion is that for any method rolling two 10s, and a number greater than 4 will be a very large total (16+ stats).
Also that my suggested method is pretty flawed, as it removed the possibility of "off the chart" totals for dice rolls. It would never produce totals in the 70s.

So I like Humboldtscott's more, and think it is an improvement on standard crit rolls. Nice work sir.


the Spreadsheet for ref: ... ations.xls

Facinating discussion, if, yes, contentious. I made it through 3 pages (having to switch from forum runner to browser to find it, and that's painful to read on the phone-screen, or I might have gotten further.

As far as I got, both sides made good cases that the RAW supported their view, and to the degree it didn't, both sides also made good cases for their way being a good house rule that allows them to tell the stories they want. It seemed that the RAW is arguably contradictory, vague, or can be read more than one way, and as such, seemed ripe for errata to clarify author's intent. Then everyone could go on arguing for the validity of the house rules they prefer.

Reminded me of this: ... ords_.html

Agreed. Not a problem in my case, as none of us have played Ars before I started this saga. But should I not botch my "make it to the grand tribunal" roll, I'll have to remember the standard, particularly if I complete my "write a con adventure" ritual first (both will definately involve stress die!). Really a problem with any house rule though.

Exactly! This is one of several problems I was trying to avoid, by having all numbers mean essentially the same thing, regardless of the die tossed or the step in the rolling process. Under my variant, you might have to ask the SG "I rolled a 1. Are there botch dice?" Or "I rolled a 10 (that is, 0). Can I roll again for a spectacular result?" But you'll never have to ask "I rolled a 1. Is that really good, or really bad?"

Perhaps ideally one should always know the die type in advance, but I can quickly think of several reasons you wouldn't. I'm a lazy SG, I don't like to describe things in rules-speak unless necessary, I might assume its clear but the troupe might not, the player may toss the die too quickly, or my story may have elements that would be unecessarily revealed if I clarified the risk factors in advance.

We use the inverted process, and not exploding dice but adding dice. If you roll a 10 (0) you can roll again. You add the new number to your 10. 1 is the one that makes you botch. So if you roll 10 + 10 + 6 you have a 26 to add to your characteristic+ability roll.

Results are more controlled and less random in pour opinion.


Hmm, perhaps. I do appreciate your comment, because these are the sort of impacts I was looking for I don't want to break the system or have to introduce a lot of situation-specific house rules; I want to simplify the basic mechanic so its more consistent.

In this case, I think I can live with the impact. The aging total includes a stress die with no botch. It has a range of 0, 2-9, and 4 to infinity for a spectacular sucess.

Mine would shift it from 1-10, with 10 to infinity for a spectacular "success." (Note that its the aging process that's rolling, a high roll means more serious effects.)

So while the lowest and highest result have shifted up by 1, I've also restored 1 to the posibilities. I've also said that a spectacular sucess will always be at least 10 - this is a rare occasion would like their re-roll to be a low number.

Frankly I'm not smart enough to figure out what all that means statistically, but I suspect that its "livable." If it means that people age a little quicker and die a little younger, I'm ok with that. A slightly darker feel explains all the more why so much effort is put into positive living conditions for those who can afford them, longevity rituals for those who know how, etc.

Note that the aging crisis is a simple die, so no change there.

I simply prefer that, if the first roll is a 10, the final result will not be less than 10. What could be more annoying than, under the RAW, rolling a 1,1,2 resulting in an 8, and then watching your opponent roll a 9? My variant, if you rolled 0,0,2, you'd be granted a 10. Also, while the low-end of my variant is higher, since 0's would always be re-rolled, the "high end" results would be 9xX rather than 10xX.

I'd considered that, as I've played other d10 based games, such as Cyberpunk 2020, that worked along that sort of linear progression. I decided to stick with the breakaway results possible with mutiplying, as my math poor mind just assumes that multiplying will produce more spectacular results than addition, on these rare occasions. I didn't want to tone down that unpredictable dramatic element.

I might switch to that if I find that unbelievably spectacular successes are becoming too frequent in my saga.

One suggestion to handle this is simply to do aging rolls as SG and use a modified roll more inline with the original just for this. (basically one where a 10 isnt automatically 10 or more)

Now that I looked at the numbers:
The RAW system has 10% to 11.1% for 2-9 and 1% for 10. Your system has exact 10% for 2-9 and 4.1% for 10. My issue was the higher chances of getting the Aging Crisis from 10+3=13, but I think your way is nicer.