# Ad-Hoc Skill Check Modifiers (complicated)

#### Matthias

##### Distinguished

I have encountered a few situations as DM where the player characters have
decided to check out the local shops. By necessity they invoke several opposed
rolls from these NPCs which did not exist moments before. I have been hoping to
be able to guesstimate the skill check modifiers for these NPCs, however, rather
than come up with abstract DC's from the general table of DC's listed in the PHB
or DMG.

I have been working on skill check modifier tables that would take into account
the NPC's probable character level, their class, whether they are using a class
or cross-class skill, and chances of how specialized they have become in that
particular skill.

For purposes of this system, I have limited NPCs to being either 1st, 5th, 9th,
13th, or 17th level. These particular levels give you a max.-ranks-value which
is evenly divisible by 4. So a character that gains 2 SP/level (ignoring Int-mod
& racial bonus SP) will get (character level + 3) x 2 SP (referred to the
character's base SP total).

Let's say that a character's skills can be classified by priority, where the
priority determins the number of SP a given skill has. Let us also say that
given 3 priority levels (low, medium, and high), they are proportional as
follows: 1:2:4. Thus low-priority skills will have N SP, med-priority skills 2xN
SP, and high-priority skills 4xN SP. (I talk about SP only, not actual ranks,
because some characters of a given class such as Fighter may consider
cross-class skills to be important enough to gain SP in, such as Tumble. In such
cases the actual no. of ranks would be 1/2 the SP put into them, but the
proportion of assigned SP to the max ranks of the skill will usually remain the
same as for class skills, excluding multiclass characters.)

Now limiting NPCs to the specific levels given above, lets us deal with base SP
that exist in multiples of 8. This lets us divide the base SP for a given
character into 8 packets of SP to assign to different skills regardless of
character level, where each packet has 1/4th the character's max ranks in SP (or
1/8th of their base SP). So a Ftr13 will have 32 base SP, and will have 8
packets of 4 SP to distribute among any skills that would be important to him.

A high priority skill would get 4 packets, making that particular skill maxed
out. A medium priority skill would get 2 packets, and a low priority skill would
get 1 packet. After this point, any skill points gained from a positive Int
modifier ((CL+3) x Int mod) or from being human (CL+3) would be assigned where
desired, presumably with the NPC's profession or specialty in mind.

NPC getting 2 SP/level will have anywhere from 2 to 8 skills with SP assigned
them (not counting the extra skills getting SP gained from high Int or racial
SP). Classes giving 4, 6, or 8 SP/level will of course have 4 to 16, 6 to 24, or
8 to 24 skills with SP.

Now there are nine permutations for low, medium, and high-priority skills with
classes getting 2 SP/level.

Low-Priority: 8 skills @ (MR/4) SP each, Med-Priority: 0 skills, High-Priority:0

At this point, you have a system that could be used to generate skill sets for
NPCs a little more quickly than it would take to generate a player character
with totally customized skill ranks. Assuming you fleshed out a set of tables
with the calculated number of SP per packet a given class would receive at a
given level, and you would have all the info you'd need to assign SP on the fly
for a new NPC.

IMO the above system is a bit more flexible than what the MM suggests about
assigning SP to new monsters, which is what this system is partially based on.
(That is, assign (HD+3) SP to a number of skills for the monster according to
how many skill points per level they receive by creature type.)

However, what I am really looking for is a set of tables that could abstract the
process still further. By limiting the SP assignment process, we might be able
to increase the level of abstraction more easily.

So far I have had some success, but these tables basically depend on a few key
questions I am having trouble determining:

What are the odds that a character of a given class & level would have put at
least one SP into a given skill if it is a class skill?

What are the odds that a character of a given class & level would have put at
least one SP into a given skill if it is a cross-class skill?

Once we know whether a character has put SP into a skill, what are the odds the
character made it a low-priority, medium-priority, or high priority skill?

After that, once we know the class, level, whether the skill gained any SP, and
what priority the skill was given, we can determine exactly how many SP (and
ranks) the NPC would have, and therefore present the player character with a
somewhat realistic opposed roll.

--

Matthias (matthias_mls@yahoo.com)

"Scientists tend to do philosophy about as well as you'd expect philosophers to
do science, the difference being that at least the philosophers usually *know*
when they're out of their depth."
-Jeff Heikkinen

#### Matthias

##### Distinguished

There was one part of this system which I forgot to finish.

Now there are different permutations for low, medium, and high-priority skills
based on this system.

L: low-priority skills (MR/4 SP each)
M: medium-priority skills (MR/2 SP each)
H: high priority skills (MR SP each)

With classes getting 2 SP/level, there are 9 permutations of priority:
L/M/H (number in each priority)
8/-/- (8 total)
6/1/- (7 total)
4/2/- (6 total)
4/-/1 (5 total)
2/3/- (5 total)
2/1/1 (4 total)
-/4/- (4 total)
-/2/1 (3 total)
-/-/2 (2 total)

With classes getting 4 SP/level, there are 25 permutations:
L/M/H
16/-/- (16 total)
14/1/- (15 total)
12/2/- (14 total)
12/-/1 (13 total)
10/3/- (13 total)
10/1/1 (12 total)
8/4/- (12 total)
8/2/1 (11 total)
8/-/2 (10 total)
6/5/- (11 total)
6/3/1 (10 total)
6/1/2 (9 total)
4/6/- (10 total)
4/4/1 (9 total)
4/2/2 (8 total)
4/-/3 (7 total)
2/7/- (9 total)
2/5/1 (8 total)
2/3/2 (7 total)
2/1/3 (6 total)
-/8/- (8 total)
-/6/1 (7 total)
-/4/2 (6 total)
-/2/3 (5 total)
-/-/4 (4 total)

With classes receiving 6 and 8 SP/level, there are many more permutations (I'm
guessing 49 and 81, respectively). One might consider having an even number of
skills of each priority level, which would pare down the number of permutations
for 2-SP/level classes to 5 and the number of permutations for 4-SP/level
classes to (apparently) 11.

--

Matthias (matthias_mls@yahoo.com)

"Scientists tend to do philosophy about as well as you'd expect philosophers to
do science, the difference being that at least the philosophers usually *know*
when they're out of their depth."
-Jeff Heikkinen

#### Spinner

##### Distinguished

> I have been working on skill check modifier tables that would take into
> account
> the NPC's probable character level, their class, whether they are using a
> class
> or cross-class skill, and chances of how specialized they have become in
> that
> particular skill.
>
Great theory to build this system. I don't have the answers to the
questions you're asking but I sure am eager to see your results.

Spinner

#### Matthias

##### Distinguished

This is related to my ongoing project of ad-hoc skill check modifiers.

I have three formulas for determining the probability that a player character of
a given class and _low_ level would have taken ranks in a cross-class skill.
(Higher-level PCs tend to have a few ranks in everything, which would make this
question a moot point.)

Please look at each set of probabilities and pick the one that seems to fit your
own experiences the best. Avoid critiquing specific scores by class, but if the
majority of the numbers seem off for a given set then rate that set poorly. I
purposefully omitted the methods used, to make it a 'blind test'.

METHOD #1
Bbn- 30% of skills are cross-class
Brd- 40% " " " " " " "
Clr- 20% " " " " " " "
Drd- 30% " " " " " " "
Ftr- 20% " " " " " " "
Mnk- 30% " " " " " " "
Pal- 20% " " " " " " "
Rgr- 40% " " " " " " "
Rog- 50% " " " " " " "
Sor- 20% " " " " " " "
Wiz- 20% " " " " " " "

METHOD #2
Bbn- 19% of skills are cross-class
Brd- 49% " " " " " " "
Clr- 15% " " " " " " "
Drd- 23% " " " " " " "
Ftr- 12% " " " " " " "
Mnk- 28% " " " " " " "
Pal- 15% " " " " " " "
Rgr- 34% " " " " " " "
Rog- 49% " " " " " " "
Sor- 11% " " " " " " "
Wiz- 20% " " " " " " "

METHOD #3
Bbn- 42% of skills are cross-class
Brd- 12% " " " " " " "
Clr- 20% " " " " " " "
Drd- 34% " " " " " " "
Ftr- 26% " " " " " " "
Mnk- 24% " " " " " " "
Pal- 20% " " " " " " "
Rgr- 42% " " " " " " "
Rog- 42% " " " " " " "
Sor- 28% " " " " " " "
Wiz- 10% " " " " " " "

--

Matthias (matthias_mls@yahoo.com)

"Scientists tend to do philosophy about as well as you'd expect philosophers to
do science, the difference being that at least the philosophers usually *know*
when they're out of their depth."
-Jeff Heikkinen

#### Matthias

##### Distinguished

On Fri, 11 Mar 2005 05:32:04 GMT, Matthias <matthias_mls@yahoo.com> wrote:

>This is related to my ongoing project of ad-hoc skill check modifiers.
>
>I have three formulas for determining the probability that a player character of
>a given class and _low_ level would have taken ranks in a cross-class skill.
>(Higher-level PCs tend to have a few ranks in everything, which would make this
>question a moot point.)
>
>Please look at each set of probabilities and pick the one that seems to fit your
>own experiences the best. Avoid critiquing specific scores by class, but if the
>majority of the numbers seem off for a given set then rate that set poorly. I
>purposefully omitted the methods used, to make it a 'blind test'.

As an addendum to this, if it makes it any clearer, these percentages *should*
represent the general amount of a character's skill points that were assigned to
cross-class skills versus class-skills. Higher-level characters have probably
spread their SP around a little more, so I am looking specifically at
lower-level characters to gain "purer" results.

--

Matthias (matthias_mls@yahoo.com)

"Scientists tend to do philosophy about as well as you'd expect philosophers to
do science, the difference being that at least the philosophers usually *know*
when they're out of their depth."
-Jeff Heikkinen

G

#### Guest

##### Guest

Time to step up the meds; I could have sworn Matthias just said...
> This is related to my ongoing project of ad-hoc skill check modifiers.
>
> I have three formulas for determining the probability that a player character of
> a given class and _low_ level would have taken ranks in a cross-class skill.
> (Higher-level PCs tend to have a few ranks in everything, which would make this
> question a moot point.)
>
> Please look at each set of probabilities and pick the one that seems to fit your
> own experiences the best. Avoid critiquing specific scores by class, but if the
> majority of the numbers seem off for a given set then rate that set poorly. I
> purposefully omitted the methods used, to make it a 'blind test'.
>
>
> METHOD #1
> Bbn- 30% of skills are cross-class
> Brd- 40% " " " " " " "
> Clr- 20% " " " " " " "
> Drd- 30% " " " " " " "
> Ftr- 20% " " " " " " "
> Mnk- 30% " " " " " " "
> Pal- 20% " " " " " " "
> Rgr- 40% " " " " " " "
> Rog- 50% " " " " " " "
> Sor- 20% " " " " " " "
> Wiz- 20% " " " " " " "
>
> METHOD #2
> Bbn- 19% of skills are cross-class
> Brd- 49% " " " " " " "
> Clr- 15% " " " " " " "
> Drd- 23% " " " " " " "
> Ftr- 12% " " " " " " "
> Mnk- 28% " " " " " " "
> Pal- 15% " " " " " " "
> Rgr- 34% " " " " " " "
> Rog- 49% " " " " " " "
> Sor- 11% " " " " " " "
> Wiz- 20% " " " " " " "
>
> METHOD #3
> Bbn- 42% of skills are cross-class
> Brd- 12% " " " " " " "
> Clr- 20% " " " " " " "
> Drd- 34% " " " " " " "
> Ftr- 26% " " " " " " "
> Mnk- 24% " " " " " " "
> Pal- 20% " " " " " " "
> Rgr- 42% " " " " " " "
> Rog- 42% " " " " " " "
> Sor- 28% " " " " " " "
> Wiz- 10% " " " " " " "
>
> Your participation will be appreciated.

I'm afraid I have to rate all of them poorly.

Your percentages are, nearly across the board, a) way too high and b)
exactly backwards about which classes go for cross-class skills the
most. Rogues, Bards and Rangers typically have everything they're likely
to want as a class skill already; yet in all cases except Bards in
method 3, you have those three classes taking the *most* cross-class
skills. It's the classes with very few and mostly mediocre class skills
(eg Fighter, Cleric) that I've seen actually spend points cross-class,
their paltry skill-point budgets notwithstanding.

#### Matthias

##### Distinguished

On Tue, 15 Mar 2005 19:13:47 GMT, Jeff Heikkinen <no.way@jose.org> wrote:

>I'm afraid I have to rate all of them poorly.
>
>Your percentages are, nearly across the board, a) way too high and b)
>exactly backwards about which classes go for cross-class skills the
>most. Rogues, Bards and Rangers typically have everything they're likely
>to want as a class skill already; yet in all cases except Bards in
>method 3, you have those three classes taking the *most* cross-class
>skills. It's the classes with very few and mostly mediocre class skills
>(eg Fighter, Cleric) that I've seen actually spend points cross-class,
>their paltry skill-point budgets notwithstanding.

No problem. I got a similar answer from another person who evaluated things.

I always figured that a class low on SP would want to play to their strengths
(i.e. class skills) as much as possible, while the high-SP classes could spread
their points around.

It could be purely a question of taste, I dunno.
--

Matthias (matthias_mls@yahoo.com)

"Scientists tend to do philosophy about as well as you'd expect philosophers to
do science, the difference being that at least the philosophers usually *know*
when they're out of their depth."
-Jeff Heikkinen

G

#### Guest

##### Guest

Matthias wrote:
> Jeff Heikkinen wrote:
> >
> > I'm afraid I have to rate all of them poorly.
> >
> > Your percentages are, nearly across the board, a) way too
> > high and b) exactly backwards about which classes go for
> > cross-class skills the most. Rogues, Bards and Rangers
> > typically have everything they're likely to want as a
> > class skill already; yet in all cases except Bards in
> > method 3, you have those three classes taking the *most*
> > cross-class skills. It's the classes with very few and
> > mostly mediocre class skills (eg Fighter, Cleric) that
> > I've seen actually spend points cross-class, their
> > paltry skill-point budgets notwithstanding.
>
> No problem. I got a similar answer from another person who
> evaluated things.
>
> I always figured that a class low on SP would want to play
> to their strengths (i.e. class skills)

Not always a valid comparison.

> as much as possible, while the high-SP classes could spread
> their points around.

High-SP classes almost always have more class skills. I think the
class most likely to have cross-class skills is the 2 SP, but
high-Int, and not particularly many class skills class: Wizard.

> It could be purely a question of taste, I dunno.

Most 2-SP classes just plain don't *get* many class skills, and those
they'd want aren't always on that list (think Dex-based Fighters and
Tumble). Other than that, I can't really add to Jeff's very well-put
explanation above.

--
Nik