A few questions were coming up in the comments section that made me realize that there are other players out there like me who really like to know mechanically what's happening under the hood of a mod.

In vanilla CK3, there are six distinct traits that each have a 3-step ladder (Beauty Good 1, Beauty Good 2, Beauty Good 3, etc.) These are all coded as three individual traits, but thanks to fancy engine magic, give the illusion that they are all connected. This was a design that predates the XP trait pathways system that was introduced to CK3 later. I believe that the three individual traits for each congenital trait is, overall, a very clunky design by comparison to the XP system track in one trait, which is what this mod tries to emulate. However, there are dozens of events, triggers, and decisions in vanilla CK3 that all look for these individual traits (e.g. has_trait = beauty_good_1, etc.) which I didn't want to individually modify.

So in A Promise of Blood, these individual trait mechanically still exist, however, the boundaries between them are very blurred. Each trait (beauty good 1, beauty good 2, beauty good 3, etc.) have the same XP pathways, and when you move from one "rank" (e.g. beauty good 1) to another (e.g. beauty good 2) the mod preserves the XP in the shift from rank 1 to rank 2 seamlessly. The icons and descriptions are also dynamic based on the XP you've accumulated, so while you might be coded for beauty good 1, if you acquire enough XP to hit the threshold, your rose bud icon might convert to a partial blooming rose without actually changing you from beauty good 1 to 2. This preserves the genetic mechanics from vanilla (another system I'd like to take a hammer to personally).

The only moment I think that takes you out of this system and breaks that seamless nature I'm looking for is the Ruler Designer at the start of the game, where you see all three traits distinctly laid out as "choices," where you can also see the pathways. Your brain, having interacted with the XP system before in CK3, goes, "Hey wait, all three of these traits have the same XP pathways with the same bonuses. Why is the third tier of Beauty so much more expensive if they're all the same?"

Here's the deal: they're not the same. I promise.

Each tier (e.g. beauty good 1, 2, or 3) has an XP pool that gets distributed at the start of the game to represent what your character was born with (the trait itself) and how nurture played a role (the XP gained). Each rank has the following XP pools:

• Rank 1: 50 XP
  
• Rank 2: 125 XP
  
• Rank 3: 200 XP

You cannot improve this XP amount after you grow up (final birthday that you accumulate XP is 18), which I know is counterintuitive to other traits that use the XP system. This might lead you to suspect there is no difference between Rank 1 and 3 of the same trait, since you're thinking, "Well, I can just get Beauty Good 1, rack up XP, and it'll be the same as getting Beauty Good 3." Nope. Doesn't work like that. If you start the game with one of these core congenital traits, you'll get a random distribution of XP to each of the pathways. For Rank 1, you might get a [5, 5, 50] or [5, 25, 25] spread, while for Rank 3, you might get a [25, 75, 100], [50, 50, 100], or [50, 75, 75] spread.

Now, in children who are born with the congenital traits, it is not this clean, though follows the same general pattern and philosophy. I wanted there to be a sense of progression that could be shaped, but not controlled, by the player, without treating these genetic traits like they are skills that can simply be trained, as that violates the spirit of CK3's design for these congenital traits. There is a certain randomness that does happen, with no player action guaranteeing a result or outcome. That being said, if you inherit what would be coded as a Rank 1 trait (e.g. Beauty Good 1) you will get capped at how much XP you can achieve on any pathway in that trait, with only Rank 3 unlocking the potential to hit 100 XP in a single pathway. So there isn't a scenario where you'd have a child being born with Rank 1 in a trait, but achieving the outcomes of a Rank 3 trait and its XP limits.

I am considering a simple mechanic that allows the player to really put their thumb on the scales of chance and control which pathway gets the most XP, but there is something about that idea that I'm struggling with, as it just feels like min/maxing to me. But I also respect that many players disagree with me on that, and greatly enjoy min/max play. If I do implement something, it'll come with a rule to turn it on or off.

Let me break down how, where, and how much XP gets assigned. The following steps occur depending on the age of the child:

• Age 0: At birth, if the child has inherited any of the six core congenital traits from their parents, that trait is immediately removed and replaced with a flag. So no more beautiful genius newborns. You won't know what you have for a while.
  
  
• Age 4: On their 4th birthday, an event fire that checks them for those trait flags. If they have them, the traits get added back in at Rank 1 with 0 XP. All ranks (1, 2, & 3) all acquire the same amount of XP for the next 6 years until they are 10. There are three pots of XP amounts awarded: 7 to 10 points in one pathway, 3 to 5 points in a second pathway, and 0 to 3 points in a third pathway. Which of the pathways gets these XP awards depends on which traits the child has, what their education focus is, if their parents have a high amount of XP in one of those pathways, if they are imprisoned, and their social class (lowborns are less likely to develop traits like endurance and visage where historically speaking access to proper nutrition and regular hygiene was limited).
  
  
• Age 11: On their 11th birthday, a child will continue to accrue some XP if they are only coded for Rank 1 of the trait (e.g. beauty good 1), but this is no more than 1 or 2 points, not enough to achieve a new rank, but provide you that desperate hope that they can pull off that next level before they become adults... and then experience utter despair when they don't meet your lofty expectations. Welcome to parenting. If, however, the child is coded for Rank 2 or 3 of the trait, they continue to gain XP as they were between Age 4 and 10 until Age 14.
  
  
  
• Age 14: On their 14th birthday, children will continue to accrue random 0 to 1 XP points per pathway, unless they have Rank 3 in the congenital trait, in which they'll continue to gain XP as described in Age 4.
  
  
  
• Age 18: On their 18th birthday, children receive their last batch of XP (trait 1 and 2 only get up to 1 point each, rank 3 gets the last pot available to it). At this point, whatever XP a character has accrued is what they will have for the rest of their life.

The list below are all the factors that are considered when deciding which pathway gets the 7 to 10 XP drop, the 3 to 5, and the 0 to 3. There is a base 33% chance for any of those three being picked.

• Education or Education Focus
  
• Reinforcing/complimentary traits
  
• Parents having high scores
  
• Social class

These are all listed in the tooltips when you hover over the individual pathways. For example, the Memory pathway (under the Intelligent trait) tooltip says: "Growth flourishes amongst the elite and alongside the Learning Education, while it is further encouraged by the Calm, Stubborn, and Temperate traits. It falters in the presence of the Gluttonous trait with it being uncommon to develop amongst the lower class." So, essentially, if you meet at least one of the criteria for the "flourishing" tooltip (e.g. Learning education, or Calm, Stubborn, or Temperate trait), your odds of picking up 7 to 10 XP in Memory jumps up by 50% (to a total of around 85% ish). However, if you have any of the faltering traits, like Gluttonous, or are part of the lower class, your odds get halved to around only 40% of getting the 7 to 10 XP dump in Memory. But there is still the 3 to 5 XP award and the 0 to 3, which gets assigned to the other two remaining pathways based on those same odds.

If it feels like the XP is being awarded randomly, odds are, you are not specializing your child with their education or their traits. If you try to generalize your child, you still get the same pool of XP overall, you're just more likely to spread that XP out over all three pathways then to get a clear specialization pathway.