RQG: Calculation of critical and special success

[hanataka]

I am reading RuneQuest: Roleplaying in Glorantha. It is most beautiful and exciting rulebook I have ever read.

But There are some glitches left in it. As one of them, There are three inconsistency rules in the probability of critical and special success.

Rule 1: Page 7."Whenever a division result creates a fraction, always round in favor of the players"

If an adventurer has 65% skill, 65/20 = 3.25, he has 4% (rounding upward) chance of critical success. If the enemy has 65% skill, he has 3% chance (rounding downward). If they have 75% skill, 75/20 = 3.75, the result is same. Adventurers have 4%, the enemies have 3%

Rule 2: Page 142. "A critical success is an ability roll of 5% (1/20) or less of the modified chance of success."

Applying this rule strictly, it becomes as follows. If an adventurer has 65% skill, 65/20 = 3.25, Rolling 03 is less than 3.25% and critical success. 04 is not. If the adventurer has 75% skill, 75/20 = 3.75, Also, a 03 is a critical success. 04 is not.  So this is the same as RQ2 and "always rounding downward".

Rule 3: Page 143.   Ability Result Table
Ability  Critical  Special
63-67      1-3      1-13
68-69      1-3      1-14
   70          1-4      1-14
71-72      1-4      1-14
73-77      1-4      1-15

This table is the same as that of RQ3. It is calculated by the following rule.
"All fractions less than .5 are dropped; fractions .5 or greater are rounded to the next highest whole number" (RQ3 Player Book p.33)

These are only small differences, but I feel the need for the fix.

As my personal opinion, Rule 2 is the most simple and best. At first glance, the calculation seems complicated, but actually, Rule 2 is not. When you roll 03, 03 x 20 = 60, the adventurer needs 60% skill or higher for critical success. When you roll 07, 07 x 20 = 140, the adventurer needs 140% skill or higher for critical success. It is very simple. Multiplication is always easier than division.

How do you think?

[David Scott]

When I started playing RQG three weeks ago, I printed the ability results table out. No one in my group has bothered with maths. 

[hanataka]

Hi, David.
If the ability result table is replaced by another one (like this extended RQ2 table), you have also no problem, don't you?

Ability  Critical  Special  Success  Failure  Fumble
-------  --------  -------  -------  -------  ------
01-04       01        --     02-05    06-95   96-00
05-09       01        --    Ability  Avility  96-00
10-14       01        02    Ability  Avility  96-00
15-19       01      02-03   Ability  Avility  96-00
20-24       01      02-04   Ability  Avility  97-00
25-29       01      02-05   Ability  Avility  97-00
30-34       01      02-06   Ability  Avility  97-00
35-39       01      03-07   Ability  Avility  97-00
40-44     01-02     03-08   Ability  Avility  98-00
45-49     01-02     03-09   Ability  Avility  98-00
50-54     01-02     03-10   Ability  Avility  98-00
55-59     01-02     03-11   Ability  Avility  98-00
60-64     01-03     04-12   Ability  Avility  99-00
65-69     01-03     04-13   Ability  Avility  99-00
70-74     01-03     04-14   Ability  Avility  99-00
75-79     01-03     04-15   Ability  Avility  99-00
80-84     01-04     05-16   Ability  Avility    00
85-89     01-04     05-17   Ability  Avility    00
90-94     01-04     05-18   Ability  Avility    00
95-99     01-04     05-19    20-95    96-99     00
100-104   01-05     06-20    21-95    96-99     00
105-109   01-05     06-21    22-95    96-99     00
110-114   01-05     06-22    23-95    96-99     00
115-119   01-05     06-23    24-95    96-99     00
120-124   01-06     07-24    25-95    96-99     00

 

Edited June 3, 2018 by hanataka

[PhilHibbs]

2 hours ago, hanataka said:

Ability  Critical  Special  Success  Failure  Fumble
-------  --------  -------  -------  -------  ------
60-74     01-03     04-12   Ability  Avility  99-00
65-79     01-03     04-13   Ability  Avility  99-00
 

Typos in the left column.

[hanataka]

5 minutes ago, PhilHibbs said:

Typos in the left column.

Thank you, PhilHibbs. I have fixed it.

[David Scott]

10 hours ago, hanataka said:

you have also no problem, don't you?

Except the pointless exercise of printing another table out. My game is internally consistent, why do I need to make more work for myself?

[soltakss]

1 hour ago, David Scott said:

Except the pointless exercise of printing another table out. My game is internally consistent, why do I need to make more work for myself?

You can never have enough tables.

[David Scott]

3 minutes ago, soltakss said:

You can never have enough tables.

You must have seen the nice ones at UKGE

https://www.boardgametables.com/

[BWP]

On 6/3/2018 at 4:16 PM, David Scott said:

No one in my group has bothered with maths. 

A statement that's always been largely true of the RQ designers (for any edition).  The RQ3 "hit points per location" table, for instance, only agrees with the written rule occasionally.  Use the table found in the rules, or create your own that matches the text of the rules?  A matter of personal preference, obviously.  Back in the day creating an accurate table required either a lot of patience in calculating and recording the results manually or access to a computer system and some programming skills.  These days it's 5 minutes with a spreadsheet program.

 

[styopa]

4 hours ago, BWP said:

A statement that's always been largely true of the RQ designers (for any edition).  The RQ3 "hit points per location" table, for instance, only agrees with the written rule occasionally.  Use the table found in the rules, or create your own that matches the text of the rules?  A matter of personal preference, obviously.  Back in the day creating an accurate table required either a lot of patience in calculating and recording the results manually or access to a computer system and some programming skills.  These days it's 5 minutes with a spreadsheet program.

Yep.

There was some discussion about whether RQG would take the opportunity to fix the broken historical hp-per-location maths, or just use the clunky RQ2 historical table.  Nostalgia wins!

[PhilHibbs]

22 hours ago, David Scott said:

Except the pointless exercise of printing another table out. My game is internally consistent, why do I need to make more work for myself?

Bully for you! But it isn't consistent with the rules as written, so I think raising an alternative suggestion is an entirely legitimate thing to do at this stage.

[Joerg]

7 hours ago, BWP said:

A statement that's always been largely true of the RQ designers (for any edition).  The RQ3 "hit points per location" table, for instance, only agrees with the written rule occasionally.  Use the table found in the rules, or create your own that matches the text of the rules?  A matter of personal preference, obviously.  Back in the day creating an accurate table required either a lot of patience in calculating and recording the results manually or access to a computer system and some programming skills.  These days it's 5 minutes with a spreadsheet program.

Whut? RQ3 bestiary (book 4 in the DeLuxe box, IIRC) had the calculations which was all that I needed, and hit point allocation tables for a number of body shapes. Most vital/protected body part aka chest 2/5 total HP, head, other body parts like abdomen and major limbs 1/3 total HP, secondary limbs like human arms or quadruped legs 1/4 total HP, lesser limbs (e.g. chitinous ones whose loss wouldn't incapacitate) 1/6 total HP.  If any sample characters deviated from this, I never noticed, because I have never bothered to look up any numbers, but always calculate on the spot unless I am using a handout (which is rarely the case). Plus there is always a chance that neither player characters nor opposition are at full HP, giving just enough wiggle room to avoid total fails. (I did translate this part of the rules to German for private use, but didn't notice any discrepancies with the table. But then possibly I just calculated the values rather than transcribing the table entries without checking the text portion or the numerical tables verbatim, rounding mathematically correct.)

RQ3 offered enchantments which would be available to major adversaries, pumping up location HP or AP - offering some wiggle room to avoid total pushovers, too. Then there was Enhance CON, which would create a few temporary total HP that could raise location HP by one or two for the duration of the spell with reasonably restrained sorcerers.

[Yelm's Light]

Same here.  I don't need a lot of the tables, I just calculate the values on the fly.  Of course, I've been doing it for decades...

[BWP]

6 hours ago, Joerg said:

Whut?

Was my point not clear?  The RQ3 chart for HP-allocation-per-location did not match the provided charts and calculations except at a few points.  You calculated everything on the fly?  Good for you, how does that alter the reality of what was presented in the rulebooks?  "Here are the calculations, here's a handy summary in case you don't want to make those calculations for yourself, whoops the summary is wrong, so sorry."  (Except that nobody bothered to say "sorry".)  I did have access to a computer and had some basic programming skills, so I printed out my own summary and used it.  Other people used the printed summary.  Doesn't matter a fig either way, as long as you're consistent with your approach in an individual campaign.

I have no idea what the relevance of enchantments or spells has to this.  Yes, there are ways you can modify the number of HPs you have in a particular location.  That has nothing to do with the inconsistency between what the rules said and the printed summary.  Or to put it another way: the rules authors told you how to calculate HPs per location, and then demonstrated that they didn't know how to use those calculations.

I'll note in passing that a consequence of using the calculations as opposed to the printed summary is that for "unusual" HP ranges (i.e., creatures with more HPs than a PC would typically have), the 0.25 for arms vs. 0.33 for most other locations in humanoids (or near humanoids) led to, say, giants with unusually spindly arms (and barrel chests).  Not any sort of problem in game play, of course, but I vaguely recall that the printed summary tended to "even out" the locations a trifle in these unusual cases.

 

[PhilHibbs]

Yes, the HP per location charts in RQ3 were approximations of the multiples presented in the rules (0.33, 0.25, 0.4 if i recall correctly), or vice versa. Despite my mathematical brain, I always just used the charts on the basis that that's what all the published stats would probably use.

[simonh]

IIRC RQ3 basically just said here are some charts you can use. If these don't cover what you need, you can use these fractions instead. I don't particularly see any need for the hand-tuned charts to be perfectly consistent with the fractions though. The fractions are just there to help out in unusual cases. Best of both world if you ask me.

Simon Hibbs

Edited June 5, 2018 by simonh

[styopa]

1 hour ago, PhilHibbs said:

Yes, the HP per location charts in RQ3 were approximations of the multiples presented in the rules (0.33, 0.25, 0.4 if i recall correctly), or vice versa. Despite my mathematical brain, I always just used the charts on the basis that that's what all the published stats would probably use.

Spiders and insects (ie with trivial limbs that don't count toward body hp) also had 0.1 I believe.

[indiebob]

Roll a d20 at the same time as you roll a d100 for the chance to hit or miss.

If you roll a hit and roll a 1 with the d20 it's a critical (this will be exactly 5% chance, no need for rounding). 

If you roll a miss and roll a 20 with the d20, it's a fumble (you'd then roll the d20 again to decide the type of fumble).

Or you could say that in either case it's a 20 to fumble or critical, depending on whether you hit or miss... mathematically it makes no difference.

Edited March 23, 2023 by indiebob

[Akhôrahil]

On 6/3/2018 at 7:20 AM, hanataka said:

Rule 1: Page 7."Whenever a division result creates a fraction, always round in favor of the players"

If an adventurer has 65% skill, 65/20 = 3.25, he has 4% (rounding upward) chance of critical success. If the enemy has 65% skill, he has 3% chance (rounding downward). If they have 75% skill, 75/20 = 3.75, the result is same. Adventurers have 4%, the enemies have 3%

I would strongly urge everyone to ditch this rule and just round in the standard way (closest integer, up if .5) for everyone. Otherwise you get senseless outcomes like enemy D4 / 2 (typical DB for thrown weapons) being different from player D4 / 2, and as you suggest, crit/special/fumble calculations become even more tricky.

[radmonger]

critical: success with an even 10s dice and digits dice of 1

special: success with a digits dice of 1 or 5.

fumble; failure with an even 10s dice and a digits dice of 0.

Zero math and within rounding errors of the rules-as-written result.

if you tone down criticals slightly, you can drop the stuff about the 10s dice and just go with ~10% chance of each. 

[PhilHibbs]

8 minutes ago, radmonger said:

critical: success with an even 10s dice and digits dice of 1

special: success with a digits dice of 1 or 5.

fumble; failure with an even 10s dice and a digits dice of 0.

Zero math and within rounding errors of the rules-as-written result.

if you tone down criticals slightly, you can drop the stuff about the 10s dice and just go with ~10% chance of each. 

Slightly quirky at the low end, in that a 5% chance has double the chance of a success being a special success. 6 also has a significantly higher special rate than it should. Other than that, it's a really interesting idea. It's a lot for some people to remember - my brain works that way, but not everyone's does. On the other hand I've seen grown men literally reduced to tears over critical and special calculations.

Edited March 23, 2023 by PhilHibbs

[radmonger]

An alternative that's a bit smoother at the lower end is to base specials off pairs (11, 22, ...).

[DreadDomain]

16 hours ago, indiebob said:

Roll a d20 at the same time as you roll a d100 for the chance to hit or miss.

If you roll a hit and roll a 1 with the d20 it's a critical (this will be exactly 5% chance, no need for rounding). 

If you roll a miss and roll a 20 with the d20, it's a fumble (you'd then roll the d20 again to decide the type of fumble).

Or you could say that in either case it's a 20 to fumble or critical, depending on whether you hit or miss... mathematically it makes no difference.

A slight variation on this:

Roll a d100 and a d20. D100 works as normal. On the d20:

• On a 1 you critical or fumble (depending if you succeed or fail on the d100)
• On a 2, 3 or 4, you special if you succeed on the d100.

[Kloster]

22 hours ago, Akhôrahil said:

I would strongly urge everyone to ditch this rule and just round in the standard way (closest integer, up if .5) for everyone. Otherwise you get senseless outcomes like enemy D4 / 2 (typical DB for thrown weapons) being different from player D4 / 2, and as you suggest, crit/special/fumble calculations become even more tricky.

This is what we do.

[Bren]

On 3/23/2023 at 7:54 AM, Akhôrahil said:

I would strongly urge everyone to ditch this rule and just round in the standard way (closest integer, up if .5) for everyone. Otherwise you get senseless outcomes like enemy D4 / 2 (typical DB for thrown weapons) being different from player D4 / 2, and as you suggest, crit/special/fumble calculations become even more tricky.

We just use a D2. No rounding required.