Homebrew Concept: Ability Cores (and improving Characteristics)

What's the idea?
Simply put: increasing a character's Ability strengthens their Cores, which act as modifiers that apply to multiple Abilities.

Core bonus applies to any related Ability.

Cores advance like Abilities, except you cannot put experience points into them directly - instead, for every point in a related Ability score, you gain one experience point in the Core.

For example, suppose you have the following Ability Scores:

  • Single Weapon 3
  • Athletics 2
  • Brawl 1

This gives you 6 "experience points" in Physical Core, for a total Score of 1. You can also choose a specialization, let's make it Single Weapon. Thus, the Abilities would have effective scores of their Ability Score + Core Score.

  • Single Weapon: 3+2=5
  • Athletics: 2+1=3
  • Brawl: 1+1=2
  • Any other physical Ability: 0+1=1

What does the change do?

It is a significant change to the system, in that a hyper-specialized characters gain a slight benefit in all other related Abilities, while non-specialists who choose to gain 1's and 2's in multiple Abilities advance in their Cores faster, thus giving them even a wider breadth of skills.

But why?

To my understanding of how humans work, when a person leans into learning something, they naturally become better at related skills by the virtue of getting generally more fit at their ability - as a simple example, someone who practices martial arts naturally becomes more physically fit, which gives them a slight edge in other related things, such as running fast etc.

Example Cores are below:

Physical Core
Applies to all physical activities.

  • Athletics
  • Acrobatics (new?)
  • Brawl
  • Single Weapon
  • Great Weapon
  • Bow
  • Thrown Weapon
  • Movement (new, for something else)
  • Legerdemain
  • Lockpicking (it's back!)
  • Stealth

Social Core
Applies to all social activities.

  • Charm
  • Guile
  • Intrigue
  • Etiquette
  • Leadership
  • Carouse
  • Bargain
  • Animal Handling
  • Folk Ken

Academic Core
Applies to the academic body of knowledges.

  • Artes Liberales
  • Civil and Canon Law
  • Common Law
  • Medicine
  • Philosophiae
  • Theology

Territory Core
Applies to territory knowledges. Contentious: May not apply to all territory knowledge; a peasant who'd spent their entire life in their hometown may have no idea of other places.

  • Continent Lore (one for each)
  • Region Lore (one for each)
  • Local Area Lore (one for each)

Hermetic Core
The same can be extrapolated for other traditions, and other organizations.

  • Code of Hermes
  • Order of Hermes Lore
  • Magic Theory

Realm Core
Applies to Realm knowledges.

  • Dominion Lore
  • Magic Lore
  • Infernal Lore
  • Faerie Lore

Focus Core
Applies to Abilities that require mental focus and care.

  • Concentration
  • Awareness
  • Hunt
  • Survival
  • Chirurgy
  • Teaching
  • Finesse
  • Penetration

For Characterisic improvement, see below the discussion. I'm interested to see what people think.


Or, you know, a core like strength, or intelligence.

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Unfortunately you can't strengthen those. It's a shame, really. That said, I'm tempted to examine improving Characteristics instead of adding new mechanics.

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In principle you could have a fitness mystery cult and improve those with initiations.
Or of course there's magic.

Of course there is magic, although I'd rather look for more obvious, central ways, if you will.

I'll note that the intent of Cores is to aid character building, in that the more you do a thing, the better you become at general activities related to that thing. Characteristics appear a very static statistic, hence why I want something more...malleable.

You could simply create a house rule to improve characteristics instead of trying to create a whole new mechanism.

That is true. I will look into those.

I like your idea in principle, but as @silveroak points out there may be other ways to do it within existing mechanics.

ERPS does this for some skills and my homebrew system also includes similar ideas for abstracting skills into groups (it's very clunky and you have to enjoy bookkeeping and arithmetic :wink: ). In general, I like the idea (which I built it into my homebrew), but there are many intersections between skills and any categorization will come up short sometime or for someone. Is there a core combat skill? Do combat skills draw from physical and combat cores?

Unlike other posters, I think that attributes are more about aspects of a skill rather than a common core.

I'm grateful for the replies! I need the engagement of others to grow and improve.

Yes, I do think somehow improving Characteristics is the way to go.

Perhaps applying this idea to the Characteristics and treating them as abilities for the purposes of improvement? See the advancement of Negative Sympathy trait for comparison to how improving negative Characteristics might look like.

Or alternatively, improving physical characteristics would be a seasonal activity all of it's own? Bodybuilding, dieting and the likes? Mental characteristics could perhaps be improved by similar margins; studying academic works, socializing, practicing speeches, taking care of your appearance and posture, stuff like that.

Here's the alternative with Characteristics. I used a framwwork similar to aging, so the number of new mechanics is reduced to a minimum.

I have three ideas for advancing Characteristics, and I'm personally a fan of #3, although the numbers could be tweaked a bit.

Strengthening a Characteristic grants Advancement Points, noted next to the Characteristic's Score.

Aging reduces Advancement Points in the Characteristic, possibly dipping into the negative.

Once the absolute value of the Advancement Points exceeds the absolute value of the Characteristic's Score, the Score changes by one, and the Advancement Points in that Characteristic are reset to zero. The change raises the Characteristic Score by one if the Advancement Point value is positive, or lowers the Score by one if the value is negative.

For example, a character has Stamina of -3. He may raise it by one (to -2) when his Advancement Points in Stamina are 4 or higher. Conversely, he must lower it by one (to -4) when his Advancement Points in Stamina are -4 or lower. After the change, the character's Advancement Points in Stamina are reset to 0. Other Characteristics remain unaffected.

Normally, you may only raise the Characteristic up to +3. Improving it further is possible only if the character once had a higher score (thanks to Great (Characteristic) for example) and lost it due to aging or some other perils.

Decrepitude hampers the advancement process.

Idea 1: Gaining one Advancement Point is a seasonal activity that takes a collective number of seasons equal to one plus the character's Decrepitude Score. For example, at a Decrepitude Score of 2, it would take three seasons. At a Decrepitude Score of 4, improving Characteristics is not possible via this method.

Idea 2: Improving an Ability by 1 in a way that utilizes the related Characteristic grants one Advancement Point in that Characteristic.

Idea 3: When improving an Ability by gaining experience points, you may instead opt to lose those experience points and instead gain one Advancement Point in a relevant Characteristic, based upon how you were strengthening the Ability. The minimum number of experience points you must sacrifice this way equals 5 + twice your Decrepitude Score, and you must do so within one season. For example, at a Decrepitude score of 2, you must sacrifice 9 experience points. Because Adventure experience caps out at five per Ability, you may only raise your Characteristics by adventure while in your prime.


But why not just treat them as Abilities?
Simply put, I don't want to track Characteristics in multiple places, so I decided the best solution was to tie them to the aging subsystem. That way, everything rounds to about the same complexity-wise.

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An interesting possibility would be to have an annual development roll, the opposite of aging, which will add a point to the most commonly used attribute in the estimate of the player or storyteller, or simply with a chart similar to the aging chart. It should have modifiers which favor youth, especially for physical characteristics, and possibly a physical age when it stops.


Thanks for posting this! I always appreciate homebrew to games I enjoy, it sparks so much fun discussion for me and my group.

This does feel like a really good direction to go in, since (as you said) it feels more correct with regards to how humans interact with learning. I also appreciate it for resolving the problem of there being no transferable skills from one ability to another. Like, being really knowledgeable about hermetic law SHOULD make you more knowledgeable about hermetic history, at least a little.

I would probably be interested in using something like this to replace Characteristics entirely, since I don't particularly like them but it's really hard to remove them without changing a lot about the underlying mathematics of many of the game's most engaging mechanics.

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It would mean most 20 year old would lose an arm wrestle to a 50 year old. What is your thinking regarding aging, and physical feats such as the capacity to run a long time, lift heavy weights, which tend to peak at a younger age?

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It all depends on when you start, when you cut off and how you adjust stats. Stats will generally start to lower at 35 from age, but if you start by raising physical stats when they are young and make only mental stats likely to rise as they age before everything shuts down and they succumb to age it could work.

Alternately if it is something that requires effort to improve (say 10xp per one stat point) then working on improving your stats will help to slow deterioration as you age as well as promoting development when you are younger.

Of course on the other hand abilities in ars are already pretty generic- "athletics" covers most of wat could be considered an "ability core" for physical activity...

Characteristics already have a cost of 1, 2, 3. You can consider your 7 char points as 35 char xp and get the same result.

If you consider the required xp are based on the Characteristic score, an Int score 2 character would needs a sum of 15 scores with AL/Philosophiae to get that "effective" Int score 3.

consider as well that 3 attribute points is a minor virtue which is the price for as 50 points in abilities, which would put the conversion at 16 ability points to a characteristic point.

There's a possibiity to do it, in a following way:

You make Aging Rolls normally, except before year 35 you make them with a simple die.

Die Roll Result
2 or less Advance chosen Characteristic by one point
3 Advance physical Characteristic by one point
4 Advance mental Characteristic by one point
5-9 No effect
10-12 Age one point in any Characteristic

And onward normally.

I only eyeballed the probabilities, though.

I still think there's likely a better way to do it, but the details escape me right now...

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I would expect a much more complex chart, one which adds some fraction of the characters age (maybe 1/5) and add physical characteristics in the lower part of the chart and mental in the upper- give the possibility of adding intelligence even after 35 as aging begins to start deteriorating the body.

If you are going to integrate it with the normal aging chart keep adding 1/10 of their age, start rolling at age 14 and have something where you treat negative aging points the same way except to improve characteristics like:
3: -1 aging point quickness
4: -1 aging point dex
5: -1 aging point constitution
6: -1 aging point strength
7: -1 aging point per
8: -1 aging point pres
9: -1 aging point com
10: -1 aging point int,
11: no aging points
12: 1 aging point any characteristic

and proceed from there. Keeping in mind that at age 14 you already roll at +2 unless there are living conditions or other considerations, and if someone has a longevity ritual the original chart should be used instead as it also prevents them from improving.

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