Critical systems in different d100 games

[Questbird]

Following on from the discussion in --

I pulled down a selection of my games from my shelf to compare how they handle criticals. Looking down the list (which dates me as a gamer; I've asterisked the ones I actually play with any frequency) you can discern some of the BRP family tree. It's notable that the concept of Special successes is only found in a few of them: RQ3, BGB, and Magic World. These days I crave more simplicity in my gaming and am inclined to use a system with only criticals. I like the idea of the doubles-as-criticals idea from OpenQuest, but I haven't used it yet.

 Basic Roleplaying (Big Gold Book) *
     Special ⅕ skill
     Critical 5% skill
     Fumble 5% of failure chance
     Any skill of 5% or higher will always have 5% chance of success
     Easy skill rolls x2 skill
     Difficult skill rolls x½ skill
 Call of Cthulhu 3rd Edition *
     Impale, for piercing guns and some melee weapons, ⅕ skill
 Clockwork and Chivalry (Renaissance), 2nd ed.
     Critical ⅒ skill, fumble on 00
     01-05 auto success, 96-00 auto failure
 Elric! *
     Critical ⅕ skill
     Impale (for thrusting and stabbing weapons) on 01
     Fumble 99-00 for skills less than or equal to 100%; for 101%+, on 00 only
 Lyonesse (Mythras)
     Critical ⅒ skill
     01-05 auto success, 96-00 auto failure
     Fumble 99-00 for skills less than or equal to 100%; for 101%+, on 00 only
 Magic World
     Special ⅕ skill,
     critical 01-05, (Errata'd to 5% of skill, thanks @NickMiddleton)
     fumble 99-00 for skill < 101%; for 101%+ on 00 only
 Mongoose Runequest (I)
     Critical ⅒ skill, fumble on 00
     01-05 auto success, 96-00 auto failure
 M-Space
     Critical ⅒ skill
     Fumble 99-00 for skills less than or equal to 100%; for 101%+, on 00 only
 Nephilim
     Critical ⅒ skill, fumble on 99-00
     Skills over 100%, critical ⅕ skill, fumble only on 00
 OpenQuest 3rd edition
     Critical on doubles roll on d100 that is less than skill
     (Approximately equivalent to ⅒ skill or just under)
     Fumble on doubles roll greater than skill
     00 auto fumble except for Master (100%)
 Runequest 3rd Ed.
     Critical 5% of skill
     Special ⅕ skill
     Fumble 5% of failure chance

 

 

Edited August 28, 2021 by Questbird
Updated Magic World critical chance

[NickMiddleton]

Magic World is incorrect - *sigh* a glitch that made it in to the print but was corrected in the revised PDF (printed page 48, pdf page 50):

Quote

CRITICAL & SPECIAL SUCCESSES, FUMBLES
The lower the D100 roll result, the better the Adventurer’s performance. A special is a roll of one-fifth or less of the Adventurer’s percentiles in a skill. Round up fractions. A critical result occurs on a roll of 1/20th of the skill rating.
It’s always possible to fail abysmally: this is called a fumble. Fumbles happen more rarely than criticals because people practice succeeding, and guard against failing.
For skills of 100 percent or less, a fumble occurs on a D100 result of 99 or 00. For skills of 101 percent or more, a fumble occurs on a D100 result of 00 only. 

I am a grumpy old grognard - I loathe "dice trick" systems that  involve analysing let alone manipulating the actual dice outcomes as other than reading them as a number, and I like the clarity and directness of "roll under, roll low"; and I have a real fondness for the asymmetry of the classic five classification of results as critical / special / success / fail / fumble.

I think it is an important, impactful feature that things we care about enough to test with actual die rolls are a step more granular on the success side than the failure side; but I am also someone who dislikes the simplistic "a fumble is automatically the most ridiculously debilitating thing that could happen to a PC".

I'll happily play other schemes (I am currently playing a home brew Conan D100 game with a distinctly OpenQuest 3 success schema in fact); but I'd never run one out of choice.

[Lloyd Dupont]

I agree with you Nick...

However it could be argued, if the skill percentage range i between 1 to 100 (i.e. no skill value beyond 100%), using all tens (i.e, 10, 20, 30, ...) as critical avoid any Math and is almost equivalent to skill/10% critical threshold. Good for Math challenged players! 🙂 

And this flipping dice mechanic, as far as I understand, is when using luck point to change failure into success, I am sure you are fine with luck point! 🙂

I am confused by this sentence though "under certain conditions (such as a critical hit) you flip the digits", this does seem pointless...

Edited August 27, 2021 by Lloyd Dupont

[Mugen]

From Steve Perrin's Quest Rules :
 

Quote

Determining # of Successes (the short form)
• Rolling within the needed % but more than ½ the needed % = 1 success
• Rolling within ½ the needed % but greater than 1/10 the needed % = 2 successes
• Rolling within 1/10 the needed % but greater than 1/100 the needed % = 3 successess
• Rolling within 1/100 the needed % = 4 successes (normally this is an 01 until the %ile gets over 150)
Player character with the higher number of successes wins. Having many extra successes is often a benefit.

From RD100 :

Quote

Advantage and Levels of Success

Whenever you roll a success, and the tens die roll is higher than the unit die, the die roll is an Advantage. Thus, 07, 33 or 45 are simple successes, while rolls of 70 or 54 are also Advantages. Failure, success and Advantage are also called levels of success on a Skill roll, with Advantage being the highest level of success and failure being the lowest. An Advantage rolls beats a failure by two levels of success, and beats a success by one level.

 

[Lloyd Dupont]

this give me some inspiration for mor clarity / better wording on some part of my homebrew rule booklet for Master of Orion! 😄

[Mugen]

BaSIC, the french edition of BRP published in magazine Casus Belli had a flat 5% chance of critical success, no matter what your skill is.

[Atgxtg]

There are also some percentile based non-D100 games that use critical rules that could be adapted to a BRP game. For instance:

• HARN uses die rolls that end on 0 or 5 as critical successes or critical failures depending on if the roll is under or over the skill roll. This is very simple and easy to adpat to BRP. It could even be expanded upon to allow for multiple success levels based upon the ones die (i.e 0 = critical, 2-3 = special, 4-9 = success).
• The James Bond RPG uses a table with 4 Quality Ratings (Success Levels),based upon 10%, 20%, 50%, and 100% of the success chance. As the game ties most results (weapon damage, distance traveled, time to complete a task)  directly to the Quality Rating the Quality Ratings were a bit more important than they tend to be in most BRP games..

[Zit]

Revolution D100 as specials ("Advantages") if you roll a success + the tens dices is greater than the units dice. No maths.

This make the chance to get an Advantage not linear : 1% for a skill score of 10%, and 45% for a skill score at 100%.

 

Edited August 27, 2021 by Zit

[Questbird]

17 hours ago, NickMiddleton said:

I am a grumpy old grognard - I loathe "dice trick" systems that  involve analysing let alone manipulating the actual dice outcomes as other than reading them as a number, and I like the clarity and directness of "roll under, roll low"; and I have a real fondness for the asymmetry of the classic five classification of results as critical / special / success / fail / fumble.

I think it is an important, impactful feature that things we care about enough to test with actual die rolls are a step more granular on the success side than the failure side; but I am also someone who dislikes the simplistic "a fumble is automatically the most ridiculously debilitating thing that could happen to a PC".

 

 

 

I'm not a fan of the dice flipping idea either. However I do sometimes find dealing with Specials and Criticals a bit too fiddly.

I did experiment with the Harn system (0 or 5 units is a critical success or failure) for my hitpointless combat system. It gives the right spread of results and and makes calculating the critical fumbles easier*. I changed it to 1 or 2 on the units die to preserve the sense of 'roll low is better'. It hasn't quite stuck (partially because I only used the hitpointless system in one campaign).

I'm no maths-phobe but late at night those 'visual' dice methods such as in OpenQuest (ie. doubles are criticals; or @deleriad's variant which adds the exact skill as a super critical), or even the "units less than tens die" method mentioned by @Zit and @Mugen have appeal.

* "5% of your chance of failure" is not intuitive for fumbles and the players have no interest in getting the calculation right anyway!

Edited August 28, 2021 by Questbird

[Mugen]

7 hours ago, Questbird said:

* "5% of your chance of failure" is not intuitive for fumbles and the players have no interest in getting the calculation right anyway!

I agree with you.

But something like "roll under the tens of your skill" doesn't require much math either. It may not be as automatic as spotting a double, but I think that when you compare 06 to 7X, it's quite obvious that it's also lower than 7. And it scales seamlessly with no extra rule or effort with skills over 100%.

You don't even have to remember if 08 is a crit or not if your skill is 75, which can be a hassle, given not all games agree on the convention to use.

[soltakss]

2 hours ago, Mugen said:

But something like "roll under the tens of your skill" doesn't require much math either. It may not be as automatic as spotting a double, but I think that when you compare 06 to 7X, it's quite obvious that it's also lower than 7. And it scales seamlessly with no extra rule or effort with skills over 100%.

That is how I do it when running Legend, Mythras or similar games. Your tens digit is your Critical chance, nice and simple. Probably better to simply knock off the last digit, though, as that is even easier for skills over 100% (Player: My skill is 130, but my tens digit is only 3. GM: But, your skill is 130, so your tens digit is 13. Player: That's not my tens digit, though, the 1 is my hundreds digit. GM: OK, just knock off the last digit. Player: Oh, yeah, that works.)

 

[Questbird]

22 hours ago, Mugen said:

But something like "roll under the tens of your skill" doesn't require much math either. It may not be as automatic as spotting a double, but I think that when you compare 06 to 7X, it's quite obvious that it's also lower than 7. And it scales seamlessly with no extra rule or effort with skills over 100%.

You don't even have to remember if 08 is a crit or not if your skill is 75, which can be a hassle, given not all games agree on the convention to use.

 

 

I don't mind this system at all, especially since it works well with my favourite system Elric! which only has criticals. Does this method work the same way for critical failures? For example, if you had 60 skill and you rolled 65, would that be a fumble? (Not that Elric! has critical failures except for a fumble on 99 or 00).

Edited August 29, 2021 by Questbird

[Mugen]

2 hours ago, Questbird said:

I don't mind this system at all, especially since it works well with my favourite system Elric! which only has criticals. Does this method work the same way for critical failures? For example, if you had 60 skill and you rolled 65, would that be a fumble? (Not that Elric! has critical failures except for a fumble on 99 or 00).

I never thought about it. Thank you!

You could do the opposite : if your tens die is equal to 9 and your units are superior to your skill's tens value, it's a critical failure. 

However, I prefer the method of having fumbles on 99-00 if your skill is under 100, and only 00 if it's above 100. More that 2% complete failure seems too much to me.

[Mugen]

22 hours ago, soltakss said:

That is how I do it when running Legend, Mythras or similar games. Your tens digit is your Critical chance, nice and simple. Probably better to simply knock off the last digit, though, as that is even easier for skills over 100% (Player: My skill is 130, but my tens digit is only 3. GM: But, your skill is 130, so your tens digit is 13. Player: That's not my tens digit, though, the 1 is my hundreds digit. GM: OK, just knock off the last digit. Player: Oh, yeah, that works.)

 

Yes, that's a better explanation than mine.

[Al.]

On 8/27/2021 at 8:11 AM, Questbird said:

Following on from the discussion in --

I pulled down a selection of my games <snip>
 Call of Cthulhu 3rd Edition *
     Impale, for piercing guns and some melee weapons, ⅕ skill
 

I think CoC also has a Critical on a roll of 01 (regardless of skill)

But skimming my copy of (2nd edition) I can't find any mention of said rule, so I may have been swayed by a house rule in a con game without realising.

[Atgxtg]

18 hours ago, Al. said:

I think CoC also has a Critical on a roll of 01 (regardless of skill)

But skimming my copy of (2nd edition) I can't find any mention of said rule, so I may have been swayed by a house rule in a con game without realising.

I believe that it is in the critical and specials table. 

[Mugen]

10 hours ago, Atgxtg said:

I believe that it is in the critical and specials table. 

@Al.It seems to me CoC didn't have rules for specials and/or criticals prior to the publication of Cthulhu Now (which was either a 2nd or 3rd edition expansion, IIRC), which also introduced localized Hit Points.

Edited September 7, 2021 by Mugen

[Atgxtg]

1 hour ago, Mugen said:

@Al.It seems to me CoC didn't have rules for specials and/or criticals prior to the publication of Cthulhu Now (which was either a 2nd or 3rd edition expansion, IIRC), which also introduced localized Hit Points.

It had criticals and impales since first edition. I remember the notes for automatic weapons with only the first bullet in a burst impaling on a special success in the 1920s Sorcebook. I believe i was the old RQ2 MAx plus rolled version of impales too. Not that crits and impales mattered much against Mythos nasties. 

I won't be home until the weekend, but if you want, when I get home, I can look it up. 

[Lloyd Dupont]

One idea I had this morning in bed...

Instead of dividing the base score.. we could succeed by a number, such as more than 30%, 60%, 90%, etc...
Of course this is very different since it allow any number of level of success instead of fixed 2 or 3 or 4 (depending)...

[Mugen]

7 hours ago, Lloyd Dupont said:

One idea I had this morning in bed...

Instead of dividing the base score.. we could succeed by a number, such as more than 30%, 60%, 90%, etc...
Of course this is very different since it allow any number of level of success instead of fixed 2 or 3 or 4 (depending)...

What do you mean ?

If I roll 30 and my skill is 75, did I succeed by 30 (I read the die) or 45 (I subtract 30 from 75) ?

Neither mechanism is really new. 

Warhammer 4th edition uses Margins of Success (the subtractive mechanism) and so did old french games Légendes and Premières Légendes in the 80s.

The other one is partly used in Pendragon (as a tie breaker), and in Fading Suns 3 first editions. Latest edition of Nephilim uses the 10s of the roll to determine the degree of success.

IMO, margins of succes are too much of a hassle to be fun. For instance, just to do one opposed roll, you need to do 3 subtractions :

-Subtract attacker's roll from his skill.

-Do the same for the defender.

-Subtract result 2 from result 1.

Simply reading the die is quicker, and is mathematically identical, but requires that you use a counter intuitive mindset, where lower is better in some cases but not always.

[NickMiddleton]

On 9/6/2021 at 6:29 PM, Al. said:

I think CoC also has a Critical on a roll of 01 (regardless of skill)

But skimming my copy of (2nd edition) I can't find any mention of said rule, so I may have been swayed by a house rule in a con game without realising.

Up to 5th edition, certain weapon attacks could impale on 1/5th rolls, and 5th introduced an OPTIONAL "Critical" on a roll of 01-05 (5.6 page 124) for combat skills. (having skimmed my 2nd, 4th and 45.6 hard copies).

Don't think non-combat skills got enhanced degrees of success in core rules until at least 6th edition, and I don't have a copy of the 1st or 6th editions.

Edited September 8, 2021 by NickMiddleton

[Lloyd Dupont]

24 minutes ago, Mugen said:

What do you mean ?

If I roll 30 and my skill is 75, did I succeed by 30 (I read the die) or 45 (I subtract 30 from 75) ?

Neither mechanism is really new. 

Warhammer 4th edition uses Margins of Success (the subtractive mechanism) and so did old french games Légendes and Premières Légendes in the 80s.

The other one is partly used in Pendragon (as a tie breaker), and in Fading Suns 3 first editions. Latest edition of Nephilim uses the 10s of the roll to determine the degree of success.

IMO, margins of succes are too much of a hassle to be fun. For instance, just to do one opposed roll, you need to do 3 subtractions :

-Subtract attacker's roll from his skill.

-Do the same for the defender.

-Subtract result 2 from result 1.

Simply reading the die is quicker, and is mathematically identical, but requires that you use a counter intuitive mindset, where lower is better in some cases but not always.

La critic here are either a fix range (like 01-05) or a divider of the skill percentage.

But I though to myself why divide for critic, why not use simple difficulty modifier.

Difficulty modifiers are not new. But I have not see them mention once for degree of success in this thread.

[Atgxtg]

On 9/7/2021 at 10:16 PM, Lloyd Dupont said:

One idea I had this morning in bed...

Instead of dividing the base score.. we could succeed by a number, such as more than 30%, 60%, 90%, etc...
Of course this is very different since it allow any number of level of success instead of fixed 2 or 3 or 4 (depending)...

One concern I'd have with that method is that it would require a certain skill score to achieve certain success levels. For instance, someone with Sword 20% can't make a skill roll by 30% let alone 60% or 90%. It will also make a 30% difference in skills much more decisive, as it will result in more success levels. For example someone with 120% skill will average 1 success level more than someone with 90%.

 

I'm not saying it's a bad method, just that it will really change things.

[Lloyd Dupont]

2 hours ago, Atgxtg said:

One concern I'd have with that method is that it would require a certain skill score to achieve certain success levels. For instance, someone with Sword 20% can't make a skill roll by 30% let alone 60% or 90%. It will also make a 30% difference in skills much more decisive, as it will result in more success levels. For example someone with 120% skill will average 1 success level more than someone with 90%.

 

I'm not saying it's a bad method, just that it will really change things.

Yes, I mention that in that my original post... and divided about it...

[Lloyd Dupont]

this also allow for an unlimited amount of success (if your skill can go high?) .. and I am not sure I like it either... I might limit the number of success to 3 or 4 anyway. But it matters in case of contested roll.. I limit to, say 4, more success than the opposition...