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The binarity of BRP skills


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It is sometimes remarked that the binary pass/fail dynamic of BRP skills can be problematic. In some circumstances a more graduted scale of success/failure might be desirable. One case may be when some skill needs to be passed in order to move an adventure forward. If the skill check fails, you're stuck and the GM needs to Deus ex Machina or fudge it. Or when you have a knowledge skill, e.g.when researching something in a library, or performing music or something like that. Having only pass/fail as options is a pretty blunt instrument for measuring these kinds of activities. For example, a chemist with 60% in chemistry would be a pretty incompetent, not to say hazardous, scientist if he/she failed utterly 40% of the time in the lab.

One alternative way of using skills in these circumstances could be to view the skill rating both as the chance of total success, as per the rules, but also the minimum level of success in case of failure (barring fumble). So the scientist rolls over 60%, does not achieve the goal but maybe 60% of it, rather than failing utterly. In some situations, the character might even be allowed to roll again until succeding or fumbling, perhaps even adding up the successive "minimum levels of success" until reaching 100% (so the 60% chemist might succeed with two failed rolls, since 60% + 60% exceeds 100%, a bit like in MERP). This is of course not suitable for all skills or situations, maybe mostly for certain knowledge and communication skills.

Thoughts?

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2 hours ago, Barak Shathur said:

Thoughts?

So many 🙂

Let's try to keep this short:

  1. If you have a "narrative" approach to gaming: you only roll when the situation is dramatic, and if the outcome is interesting either way. You don't roll if it's not. So don't roll for a mundane chemical test in the lab unless you want the possibility that something explodes or the virus gets out or the PCs don't get the advantages of the new chemical compound that protects from the alien mind control or whatever.
    1. Most characters would have, say, 40% in Drive Automobile and 50% in their native language. It doesn't mean they crash their car on the way to work 2/3rd of the time, or speak gibberish while ordering coffee at the local cafe half the time!  They simply wouldn't roll in these situations!
  2. If you have a "simulationist" approach to gaming: in virtually all systems, the stat scores define the chances of success for an "adventurous" action out there in the field. So the 60% Chemistry score is only used as-is in stressful situations or whatever. Give bonuses for proper or extra time (+30%?), access to a fully stocked lab (+40%?), having a lab assistant, etc.
    1. Back to the Drive Automobile/Native Language skills mentioned above, you can apply the same reasoning and say that driving under the speed limit on a normal road with nobody chasing you or firing at you gives you +60%, and conveying simple intentions like "I'd like a coffee please" also give equally high bonuses.
  3. BRP doesn't necessarily have a binary pass/fail dynamic. Some variants of BRP offer different degrees of success and failure (RQ and CoC have 5 degrees in total).
  4. Remember that "failure" is not necessarily what you think it is. A CoC investigator who searches for information on an evil cult in the Boston Library may still find what she wants even after failing the Library Use roll... what was the roll for then? Well, it could have been for finding extra information (which she didn't, she only found the very minimum), or it could have been for finding it quickly (which she didn't... she spent the whole day in the library and now the evil cult has kidnapped another puppy for sacrificing), etc. You get the point.
    1. Going back to the "narrative" approach to gaming from (1), if failure isn't interesting and will block the story, don't do it! But, as illustrated above, you can still have rolls and get advantages from a good roll.

 

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Ludovic aka Lordabdul -- read and listen to  The God Learners , the Gloranthan podcast, newsletter, & blog !

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That was one of the things I like about the James Bond RPG.

What it did was use an ease factor (skill muitplier) to determine the actual success chance. So a skilled scientist doing a routine task would succeed about 95-99% of the time. BRP has something similar with the difficulty ratings, but the multipliers are much bigger, as the base skill is higher. 

 

Now to be fair to BRP, rolls are supposed to be made only when the situation is stressful, so a chemist in the lab would probably not have to roll for day to day tasks, anymore than they would have to roll their 30% driving skill to get back and forth to work everyday.

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2 hours ago, Atgxtg said:

What it did was use an ease factor (skill muitplier) to determine the actual success chance. So a skilled scientist doing a routine task would succeed about 95-99% of the time. BRP has something similar with the difficulty ratings, but the multipliers are much bigger, as the base skill is higher. 

Yes, ease factors and quality of success were great innovations of JB007.

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2 hours ago, Lloyd Dupont said:

After much thinking I think I will stick with multiple of +-20% or 30% (still undecided)

Multiplier are great, but my group is bad at Maths.... 😕 

Ah how about bonus dice? Similar effect but without the math. 

 

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6 hours ago, Kloster said:

Yes, ease factors and quality of success were great innovations of JB007.

It is a great RPG- it is so well adapted to the genre. I don't think QRs are really that much of a innovation- it's basically the same as RQ success levels, but with 4 grades of success instead of 3.

 

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26 minutes ago, Atgxtg said:

Ah how about bonus dice? Similar effect but without the math. 

 

I thought about it, after speeding through CoC rules....

What decided me against it eventually (in favor of an easy +20/30 modifier) was the list of bonus / malus one can apply when using projectile weapons against various target...

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12 hours ago, Atgxtg said:

Now to be fair to BRP, rolls are supposed to be made only when the situation is stressful, so a chemist in the lab would probably not have to roll for day to day tasks, anymore than they would have to roll their 30% driving skill to get back and forth to work everyday.

Speaking as the chemist in the lab, it is a stressful and potentially dangerous environment quite often, and failures are common, too. Quite often those failures result just in extra work, some broken glass, and slight exposure to toxic or corrosive spill - usually while being protected, or under somewhat controlled circumstances.

 

Driving is another case where failures are fairly common, and then trigger a series of rolls to deal with the situation to escape real damage. It takes a number of botched rolls to have really bad consequences - rolls not just by yourself, but also by other participants in traffic.

 

Basically, you can call for a roll already in a mildly stressful situation, and a fail will lead to "saving throws" to cope with the situation, or to loss of a resource (like time).

 

You don't have to roll everything. You could do a blanket roll for the quality of your day, and if you get an interesting result (of whichever kind), you might have something to roll for that may give you skill checks. You might earn or lose minor rewards (like saved time, or lingering benefits) on non-interesting results.

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Telling how it is excessive verbis

 

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You can use the 10s of your roll as a Degree of Success.

If your chances of success are >100, add 1 to your DoS per 10% above 100.

Also give bonus chances of success depending on the situation. If your 60% Chemist is doing a manipulation any student with 10% could do with a relatlively good chance of success, give him a huge bonus. As the bonus will rise his skill above 100%, his success level will rise in the same time.

I'd also use the following critical success rules : If your roll is under the tens of your skill (or a double if you prefer this method), read the die as being 10.

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15 minutes ago, Mugen said:

Also give bonus chances of success depending on the situation. If your 60% Chemist is doing a manipulation any student with 10% could do with a relatlively good chance of success, give him a huge bonus. As the bonus will rise his skill above 100%, his success level will rise in the same time.

This leads to something like a task rating in percentiles, reeking of opposed rolls.

It doesn't take more than a 10% skill to successfully produce nitroglycerine in small batches if your augmenting rolls (like "read procedural script") succeeded and your prep-work succeeded, as well as your concentration rolls. With that number of "if"s, the reaction going boom prematurely has a fairly good chance, though.

The experienced practitioner will know the pitfalls and look out for those. That can be a very narrow but deeply specialized knowledge. A meth cook with six-figures sales from his production won't be able to be very useful when starting in an analytical lab, and an experienced analytical chemist may still trigger a number of the pitfalls the meth cook knows inward and outward when trying his hand at Breaking Bad. That said, triggering the pitfalls and avoiding the fallout may be two different rolls.

Telling how it is excessive verbis

 

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4 hours ago, Atgxtg said:

I don't think QRs are really that much of a innovation- it's basically the same as RQ success levels, but with 4 grades of success instead of 3.

Yes, correct. What I meant is that 'the combination of EF and QR' was a great innovation.

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You could have a Critical/Special/Success/Success But, Fail But/Fail/Fumble Progression.

  • Critical: You roll between 1 and 1/20th of your chance to succeed
  • Special: You roll between your Critical Chance + 1 and 1/5th of your chance to succeed
  • Success: You roll between your Special Chance + 1 and your chance to succeed
  • Success But: You roll between your your chance to succeed + 1 and your chance to succeed + Critical Chance
  • Fail But: You roll between your your Success But chance + 1 and your chance to succeed + Special Chance
  • Fail: You roll over your Fail But Chance, but 96-100 is always a Fail, if not a Fumble
  • Fumble: 100 - your Failure Critical Range

So, someone with a 60% skill has the following:

  • Critical: 01-03
  • Special: 04-12
  • Success: 13-60
  • Success But: 51-63
  • Fail But: 64-72
  • Fail:73-97
  • Fumble: 98-100

You could have Fail But as your success but chance + Special again, to give Players a chance, so would be 72-84, with Fail 85-87.

Success But means that you have succeeded but there is a consequence, depending on the circumstances.

Fail But means you have failed but with a qualification, maybe you have gained insights from the failure or can try again without penalty.

 

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There's also the Opposed Roll table that dates back to early RQ.  The quality of the player's success or failure is compared against the quality of an opposing force's roll on a matrix.  Results like Criticals and Fumbles still count, but a Critical vs Critical isn't such a big deal, while Critical vs Fumble is truly monumental.

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On 4/23/2021 at 7:33 PM, lordabdul said:
  • If you have a "narrative" approach to gaming: you only roll when the situation is dramatic, and if the outcome is interesting either way. You don't roll if it's not. So don't roll for a mundane chemical test in the lab unless you want the possibility that something explodes or the virus gets out or the PCs don't get the advantages of the new chemical compound that protects from the alien mind control or whatever.
    1. Most characters would have, say, 40% in Drive Automobile and 50% in their native language. It doesn't mean they crash their car on the way to work 2/3rd of the time, or speak gibberish while ordering coffee at the local cafe half the time!  They simply wouldn't roll in these situations!
  • If you have a "simulationist" approach to gaming: in virtually all systems, the stat scores define the chances of success for an "adventurous" action out there in the field. So the 60% Chemistry score is only used as-is in stressful situations or whatever. Give bonuses for proper or extra time (+30%?), access to a fully stocked lab (+40%?), having a lab assistant, etc.
    1. Back to the Drive Automobile/Native Language skills mentioned above, you can apply the same reasoning and say that driving under the speed limit on a normal road with nobody chasing you or firing at you gives you +60%, and conveying simple intentions like "I'd like a coffee please" also give equally high bonuses.

I'm highly simulationist, but even so, I wouldn't have someone roll for mundane everyday tasks. It's more that even during stressful situations, someone with a relatively higher skill would have a higher floor than a less skilled practicioner, barring fumble. 

On 4/23/2021 at 7:33 PM, lordabdul said:

BRP doesn't necessarily have a binary pass/fail dynamic. Some variants of BRP offer different degrees of success and failure (RQ and CoC have 5 degrees in total).

It has three levels of success but only two for failure, complete failure and utter disaster, so in that sense it is kind of binary. What I'm looking for is a "partial failure" function.

On 4/23/2021 at 7:33 PM, lordabdul said:

Remember that "failure" is not necessarily what you think it is. A CoC investigator who searches for information on an evil cult in the Boston Library may still find what she wants even after failing the Library Use roll... what was the roll for then? Well, it could have been for finding extra information (which she didn't, she only found the very minimum), or it could have been for finding it quickly (which she didn't... she spent the whole day in the library and now the evil cult has kidnapped another puppy for sacrificing), etc. You get the point.

  1. Going back to the "narrative" approach to gaming from (1), if failure isn't interesting and will block the story, don't do it! But, as illustrated above, you can still have rolls and get advantages from a good roll.

 

This is exactly what I'm talking about. My system would function just like this. With Research 60%, that would mean 60% chance of getting 100% of the information available, while a normal failure would net 60% of it. 

As some in this thread have mentioned, a "special failure" might add some attenuation to the scale. I would say if you roll above the highest 1/5 of the chance to fail (with a skill of 50% this would mean a roll of 90+) it's a total failure, while anything between your skill rating and that number would mean partial failure as per the above. Now, having to calculate the special failure range for each skill is just another computing headache, so a simpler solution would be to lift it straight from the brilliant Harnmaster and have any roll that ends on a 5 or a 0 being a special roll.

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On 4/23/2021 at 11:01 AM, Barak Shathur said:

It is sometimes remarked that the binary pass/fail dynamic of BRP skills can be problematic. In some circumstances a more graduted scale of success/failure might be desirable. One case may be when some skill needs to be passed in order to move an adventure forward. If the skill check fails, you're stuck and the GM needs to Deus ex Machina or fudge it. Or when you have a knowledge skill, e.g.when researching something in a library, or performing music or something like that. Having only pass/fail as options is a pretty blunt instrument for measuring these kinds of activities. For example, a chemist with 60% in chemistry would be a pretty incompetent, not to say hazardous, scientist if he/she failed utterly 40% of the time in the lab.

One alternative way of using skills in these circumstances could be to view the skill rating both as the chance of total success, as per the rules, but also the minimum level of success in case of failure (barring fumble). So the scientist rolls over 60%, does not achieve the goal but maybe 60% of it, rather than failing utterly. In some situations, the character might even be allowed to roll again until succeding or fumbling, perhaps even adding up the successive "minimum levels of success" until reaching 100% (so the 60% chemist might succeed with two failed rolls, since 60% + 60% exceeds 100%, a bit like in MERP). This is of course not suitable for all skills or situations, maybe mostly for certain knowledge and communication skills.

Thoughts?

For me, Difficulty Ratings have ALWAYS been a thing in my Runequest and CoC campaigns.  I simply multiply the PC's (and NPC's) Skill level by the following Difficulty Ratings. 

EASY TASKS:  2 X Skill

ROUTINE TASKS:  1.5 X Skill

AVERAGE TASKS (the default level):  Skill

FAIRLY DIFFICULT TASKS (not often used):  0.75 X Skill

DIFFICULT TASKS:  0.5 X Skill

FORMIDABLE TASKS:  0.25 X Skill

IMPOSSIBLE TASKS: 0.1 X Skill

    To make my Special Successes easier to follow, I have THREE LEVELS of Special Success...

1/2 SKILL OR LESS IS ROLLED:   This gives a small special effect.  I use the SEs from MYTHRAS in my games so you would get to choose one from the list for half skill success.

1/10th SKILL (rounding up):  This is a more powerful SE list including the Crush, Impale and Slash of older RQ2. 

DOUBLES UNDER SKILL (treating 00 as zero, zero, not 100):  This is my Critical Success level.  All of the most potent SEs like COMPEL SURRENDER are located on this chart.  With Skills above 100, only a roll of 99 is a Fumble. 

DOUBLES OVER SKILL:  This is my Fumble roll.  

         I use these with every game I play that is either percentile or D20 based. 

 

     

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17 hours ago, Kloster said:

Yes, correct. What I meant is that 'the combination of EF and QR' was a great innovation.

Yeah, I've been working on a way to replicate that without a table. Something along the lines of rolling multiple dice against the Primary Chance instead of a %-dice roll. 

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On 4/24/2021 at 8:25 PM, olskool said:

    To make my Special Successes easier to follow, I have THREE LEVELS of Special Success...

1/2 SKILL OR LESS IS ROLLED:   This gives a small special effect.  I use the SEs from MYTHRAS in my games so you would get to choose one from the list for half skill success.

1/10th SKILL (rounding up):  This is a more powerful SE list including the Crush, Impale and Slash of older RQ2. 

DOUBLES UNDER SKILL (treating 00 as zero, zero, not 100):  This is my Critical Success level.  All of the most potent SEs like COMPEL SURRENDER are located on this chart.  With Skills above 100, only a roll of 99 is a Fumble. 

DOUBLES OVER SKILL:  This is my Fumble roll.  

         I use these with every game I play that is either percentile or D20 based.      

Hmm, that looks oddly familiar. 😉

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