Implant Resilience Doubling Value: Vanilla 0, Default $1500
//Resilience doesn't show up as a stat on any tooltips or infoscreens, so I have no idea how it works. It sounds like it does two things:

//Lethal damage resistance. A broken bionic arm does less damage to your "total health" than a broken and bleeding flesh arm, and therefore contributes less to the Lethal Damage Threshhold. Since most bionics are at least $1500, this means most bionics are effectively 2x as durable for the purposes of lethal damage, even if the HP of the arm itself isn't impressive.

//Part break chance. I assume this increases the chance that a limb survives with 1HP instead of being destroyed completely. Again, doesn't increase the total combat power of a pawn, but makes surviving and recovering easier.

Mutation Resilience Bonus: Vanilla 0, Default 50%
//As above, but applies to "mutations" from certain mods instead of bionics. I have no idea how it scales. It might be +.5 per body part, it might be "scaled such that when 50% of body parts are mutated, resilience doubles."

Fatal Damage Base HP: Vanilla 150, Default 100
//IIRC the vanilla fatal damage threshhold is 100, so this there must be some arcane calculations in vanilla that modify the base hp value. Apparently this mod author thought it would be easier to balance his calculations on a round number like 100 instead of 150. That or he made a typo.

Fatal Damage Animal Resilience: Vanilla 100, Default 60.
//This mod significantly reduces an animals odds of survival.

Fatal Damage Mechanoid Resilience: Vanilla 100, Default 80
//This mod slightly reduces a mechanoids odds of survival.

Fatal Damage Player Resilience: Vanilla 100, Default 250
//Significant increase to a player colonist odds of surviving otherwise lethal wounds. I'm not complaining, especially given that it's usually the bleeding that kills, not the bullet.

Fatal Damage, Limb Effect: Vanilla 100, Default 50
//I think this reduces how much losing a limb affects "total health". This is fairly realistic, as losing limbs is generally quite survivable provided the bleeding is dealt with.

Fatal Damage, Destroyed Effect: Vanilla 100, Default 200
//I think this means that completely missing limbs/organs affect "total health" more than damaged limbs. Sounds realistic.

Fatal Damage, Threshhold: Vanilla 0, Default 10
//No idea. I think it's the maximum possible damage reduction from a good "resilience" roll vs incoming damage. Ie, a 45 damage charge lance shot could be reduced to "only" 35 damage.

12 damage to torso (15.6%) 18 damage to hand (50%) 25 damage to head (75%) 30 damage to head (100%)
//No idea. Changing the sliders below adjusts this. It would seem that high percentages are good, low percentages are bad. Maybe it's the chance for damage to be negated? Ie, 12 damage to the torso has a 15.6% chance of being reduced by the part break threshhold?

Part Break, Global Resilience: Vanilla 100, Default 80
//A multiplier to part health. Ie, at 200% a heart has 30 hp instead of 15hp?

Part Break, Internal Resilience: Vanilla 100, Default 150
//A multiplier to organ/bone hp?

Part Break, Delicate Resilience: Vanilla 100, Default 75
//Brains and eyes are squishy.

Part Break, Player Resilience: Vanilla 100, Default 150
//I'm not complaining.

Part Break, Threshhold: Vanilla 0, Default 10
//Assuming the Fatal Damage, Threshold is the maximum damage reduction against potentially lethal shots, I assume this is the same but for potentially limb destroying shots.

Scarring, Global Bias: Vanilla 50%, Default 100%
//In exchange for less lethal injuries against the player, get ready for more battlescars. For a storyteller game, that sounds reasonable.

Scarring, Severity Bias Effect: Vanilla 100%, Default 50%
//Makes small scars more common than big scars.

Scarring, Bleed Rate Effect: Vanilla 0%, Default 50%
//I think this makes freshly scarred injuries bleed more. I'm unsure of the wording though.

Scarring, Part Effect: Vanilla 100%, Default 0%
//Apparently vanilla favors putting scars on some body parts over others. This mod disables that, so scars are more equally likely to occur on all body parts. This has the side effect of increasing the odds of scarring organs, I assume.

Scarring, Capacity Bias: Vanilla 100%, Default 200%
//Here it is! This makes scars more likely on vital organs.

Scarring, Delicate Bias: Vanilla 100%, Default 200%
//Here it is again, this time for brains and eyeballs. I always found it odd how often vanilla colonists heal back to full after having their eyeballs at 1/10 hp.

Scarring, Non Player Bias: Vanilla 100%, Default 100%
//Change this if you want too... disable scarring the people you are killing? Or add extra scars to people you are killing? Not sure why this is a setting, but here it is.

Scarring, Minimum Fraction: Vanilla 0%, Default 10%
//Damage that causes scars is reduced by this %, to produce a scar of this %'s worth of damage. I think.

Scarring, Maximum Fraction: Vanilla 80%, Default 75%
//Basically, this mod means wounds that scar are less likely to scar as much, but in exchange less damage is mitigated by the scarring process.

Scarring, Threshhold: Vanilla 0, Default 1
//Any scar too small to notice isn't worth putting up with.

Scarring, Maximum Reduction from Tending: Vanilla 0, Default 67%
//Healing a freshly scarred wound at 100% tend quality reduces scarring by this amount. This makes post-battle triage far more important. It actually makes glittermeds worth using as part of post battle triage - especially on organ wounds.

Bleeding, Global: Vanilla 100%, Default 125%
//Increases the initial bleed rate of wounds.

Bleeding, Internal: Vanilla 100%, Default 300%
//Gut wounds bleed more finger wounds.

Bleeding, Delicate: Vanilla 100%, Default 200%
//Head/eye wounds bleed more.

Bleeding, Non Player: Vanilla 100%, Default 150%
//Enemies bleed faster. This gives you a chance to save them for recruiting, while also killing them fast enough to save your FPS.

Bleeding, Fresh: Vanilla 100%, Default 60%
//Initial bleed rate multiplier. By Default, initially wounds don't bleed that much.

Bleeding, Fresh Duration in Hours: Vanilla 0, Default 4
//Wounds are considered fresh for 4 hours. I assume this impacts bleed rates, tending, and infection chances.

Bleeding, Old: Vanilla 100%, Default 20%
//Late bleed rate multiplier. By Default, any wounds that have survived untreated past the Fresh duration start clotting and bleed less.

Bleeding, Old Duration in Hours: Vanilla 0, Default 12
//How long it takes for an Old wound to scale from 100% bleeding to it's new value, which by default is 20%. This means a wound must survive untreated for 16 total hours to fully benefit from the slowest bleed rate.

Pain, Global: Vanilla 100%, Default 125%
//Increases pain values from injuries across the board. Wimps beware!

Pain, Internal: Vanilla 100%, Default 300%
//Gut wounds hurt.

Pain, Delicate: Vanilla 100%, Default 300%
//Poked eyes hurt.

Pain, Non Player: Vanilla 100%, Default 100%
//I wouldn't mess with this.

Pain, Fresh: Vanilla 100%, Default 40%
//It takes a moment for pain to set in. Initial pain is a bit under half it's full value.

Pain, Fresh Duration in Hours: Vanilla 0, Default 1
//After an hour, pain reaches it's full value.

Pain, Old: Vanilla 100%, Default 50%
//Old injuries only hurt half as much.

Pain, Old Duration in Hours: Vanilla 0, Default 6
//It takes 6 hours for an old injury to reach it's lowest pain value.

Pain, Scar: Vanilla 100%, Default 50%
//Halves the pain penalty from scars.

Pain, Old Scar: Vanilla 100%, Default 20%
//More than halves the pain from old scars.

Pain, Old Scar Duration in Days: Vanilla 0, Default 60
//It takes about a year to get used to a scar.


//Note: I see no mention in the settings of scars not lowering part health/part destruction chances. I have no idea how that works, but it's mentioned as a feature on the mod page.

Infection, Global Chance: Vanilla 100%, Default 100%
//No change.

Infection, Internal Chance: Vanilla 100%, Default 300%
//Triples the odds of organ infection.

Infection, Delicate Chance: Vanilla 100%, Default 300%
//Triples the odds of eye infection.

Infection, Non Player Chance: Vanilla 100%, Default 300%
//Triples the odds of prisoner infection. Don't know if it applies to guests/refugees, but I'd assume not.

I could probably figure out more, since the mod author packaged the source files with the mod, but I think that's enough of a write up for one day. I'd love to see the mod authors opinions/experience/testing that resulted in these numbers - particularly the exact mechanics of destroying part, the lethal damage threshhold, and the damage mitigation.

There seems to be a slight bias in favor of the player colonists surviving initial injuries, but in exchange scarring and infection are more dangerous. The mod description also mentions a greater chance of organ injuries. This should result in a far more dramatic combat and post combat experience.

First of all, I appreciate you taking the time to try and figure stuff out.

As for feedback/corrections:

One Shot Protection:
Correct, injuries being reduced to part health minus 1 sometimes is one-shot protection working in vanilla.


Down protection:
The storyteller setting does still affect the original routine that determines if a pawn should buy the farm when they get downed. However, down protection is a random chance to force a specific outcome, a positive value means there's an X% chance to force down instead of death, and a negative value means there's an X% chance to force death instead of down.


Resilience:
You're not far off. It does affect fatal damage and part break. The way it does that is by affecting the "effective hp" of pawns/parts.

For part break, it's fairly straightforward, it modified the amount of damage the part can take before breaking, based on the value of implants/replacements, a $1500 implant adds 100% health, a mutation(implant/replacement with $0 market value) adds 50% health.

For fatal damage, having bionics/implants just improves overall toughness based on how much coverage the implants/bionics have and the same market value/mutation check as above.

It's not specific to damage applied to implanted/replaced parts because detecting if an injury is done to a implanted/replaced part is relatively heavy on the CPU. Which makes it a poor fit for a piece of code that is frequently called.


Part Break:
"12 damage to torso (15.6%) 18 damage to hand (50%) 25 damage to head (75%) 30 damage to head (100%)"

The percentage refers to how much part break would be inflicted by a single instance of damage with X damage to Y part.

You're correct about all other things, except for what threshold does, it's the maximum amount of damage ignored per injury, but the math behind it is relatively arcane, summarized, small injuries get reduced more than big injuries.


Fatal Damage:
You're mostly right here, but, fatal damage is deterministic, there's nothing to do with odds/chance.

Base game fatal damage limit is 150 (from the last look I had through disassembly, could be 100 now?), I reduce this slightly because of the reduced amount of fatal damage coming in due to the threshold effect.

Limb Effect applies to injuries to your limbs, limbs are parts that have manipulation/movement tags. This means that a wound to a leg does less fatal damage compared to a wound to your torso or head.

Destroyed Effect applies to "missing part" injuries, I treat these as a single injury dealing 200%(default) part base hp. Not perfect, but it should be acceptable in most cases. Be aware that all other modifiers, like limb effect, still apply.


Scarring:
Almost completely correct.

Bleed effect means that injuries to parts that bleed more(organs, neck, head) scar more as well, conversely, parts that bleed less(bones, etc) scar less.

Part effect, mostly right, this also makes it possible for bone injuries to become "scars", fractured/broken bones can result in permanent discomfort/loss of function.


Bleeding:
Almost completely correct.

Wound freshness has no impact on scarring/infection.
Delicate applies to brains and eyes, not heads and eyes.
For clarity, fresh/old goes from [fresh value] initially to 100% at [fresh duration] to [old value] at [fresh duration + old duration]


Pain:
Almost completely correct.

It takes [1+6] hours for an injury to become old.

Scars don't count towards fatal damage OR part break, only fresh injuries do.


Infection:
Completely correct.

Non-player specifically refers to pawns that are not part of the player's faction, I think quest refugees/guests are temporarily added to the player faction?

Is calculation of "delicate" base on "internal", for example like: a wound caused 2 point pain in left arm bone, so if when this wound is on eye, it cause 2 * "delicate" point pain?
Or it's separated calculated?

What is "Effectiveness resilience bonus"? Is it mean this below?
There are some name changed from #20221004 in this page. But I think them still misunderstanding for little knowledge about programing as like me, due to short in-game description.