From eb4b040a0420edcc141c632b2cdb462b033d6bd9 Mon Sep 17 00:00:00 2001
From: Pickle-Coding <58013024+Pickle-Coding@users.noreply.github.com>
Date: Sat, 17 Jun 2023 04:35:47 +0100
Subject: [PATCH] Multiplicative armour penetration. (#75925)

## About The Pull Request
Basically #71396 but for armour penetration. The formula gets changed to
be the inverse function of stacking armour. An example is if you had 75%
armour. That is equivalent to having two sets of 50% armour stacked. If
the armour wearer gets hit by a 50% armour penetrating force, it is the
same as losing a piece of armour worth 50%, knocking the 75% protection
down to a 50% protection, instead of 25%.
## Why It's Good For The Game
Makes it more consistent with how armour stacking works. It also lets
very strong armour be less fragile to small armour penetration. Kinda
silly for 90% armour value to be half as effective if it gets hit by 10%
armour penetration. This also allows it to be much easier to balance
lavaland armour and fauna piercing, allowing fauna to pierce through
crew armour while still letting mining armour have significant
protection. That isn't included in this balance change, but it allows
the option for someone to do that without changing any armour values.
## Changelog
:cl:
balance: Armour penetration calculation is now the inverse function of
armour stacking.
/:cl:
---
 code/modules/mob/living/living_defense.dm | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/code/modules/mob/living/living_defense.dm b/code/modules/mob/living/living_defense.dm
index 4e8fe489b2e..9be2387a482 100644
--- a/code/modules/mob/living/living_defense.dm
+++ b/code/modules/mob/living/living_defense.dm
@@ -11,7 +11,7 @@
 
 	//the if "armor" check is because this is used for everything on /living, including humans
 	if(armour_penetration)
-		our_armor = max(0, our_armor - armour_penetration)
+		our_armor = armour_penetration == 100 ? 0 : 100 * max(our_armor - armour_penetration, 0) / (100 - armour_penetration)
 		if(penetrated_text)
 			to_chat(src, span_userdanger("[penetrated_text]"))
 		else