Creature version here. Original (patcher) version here.

Know Your Enemy Redux fixes Skyrim's repetitive combat by changing the resistance and susceptibility of armors to different weapons and spells. The end result is that you will need to tailor your strategy to the current foe and bear in mind the strengths and weaknesses of your own gear when in combat.

• Armors are given traits that affect their resistances and weaknesses.
• Weapons are split into blade, axes, blunt and arrows (fists count as blunt) while spells are split into fire, frost, and shock.
• Physical resistances and weaknesses modify your effective armor rating when attacked.
• Magical resistances and weaknesses modify your elemental resistance stats.
• All vanilla armors are affected, as well as many of others added by mods, and all done seamlessly via SPID.
• It is only the cuirass that matters, not gloves, boots or helmets.
• The player is given a spell to reveal a target's armor's traits (with an optional patch to make it a lesser power)
• You can see the effects of your own armor in your active effects list.
  

There are seven total traits, four concern an armors material, the other three concern its construction. Each armor is given appropriate traits - between 1 and 3 depending on the piece - and they combine to determine its overall resistances and weaknesses. The player is also given a spell, "inspect armor", that when cast on a target reveals the traits of their worn armor (there is a patch in the optional downloads to make it a lesser power if you prefer). The traits are:

Material: Fur
Fur is common in early-game light armors, but is included in many late-game armors too.
Resistances: Frost (+50%).
Weaknesses: Arrows (x0.5 AR).

Material: Leather
Leather is a typical early-game light armor material.
Resistances: Fire (+25%).
Weaknesses: Arrows (x0.75 AR).

Material: Metal
Metal is characteristic of early and mid-game heavy armors.
Resistances:  Blades (x1.5 AR), Arrows (x1.5 AR).
Weaknesses: Shock (25%).

Material: Nonconductive
Nonconductive materials like glass, moonstone, ebony and bone, are typical of late game armors.
Resistances:  Shock (75%).
Weaknesses: Fire (25%), Frost (25%), Blunt (x0.75 AR).

Construction: Layered
Layering reduces the penetration of arrows and is common among light armors.
Resistances:  Arrows (x1.5 AR).

Construction: Thick
Thick plates resist arrows and blades, but can weigh a lot.
Resistances:  Blade (x1.5 AR), Arrows (x2 AR).

Construction: Deep
Plate armors with padding between armor and wearer are resistant to axes and blunt weapons.
Resistances:  Axes (x1.5 AR), Blunt (x2 AR).

Armors

The player is given the spell "inspect armor" to see a target's armor's traits, but some examples, including the combined effects of different traits, are shown below:

Leather: Leather.
Resistances: Fire (25%).
Weaknesses: Arrows (x0.75 AR).
Note that the arrow weakness affects the armor rating, meaning the armor is less effective, but still better than wearing nothing.

Studded: Leather, Layered.
Resistances: Fire (25%), Arrows (x1.125 AR).

Elven: Nonconductive, Layered.
Resistances: Shock (75%), Arrows (x1.5 AR).
Weaknesses: Fire (25%), Frost (25%), Blunt (x0.75 AR).

Glass: Nonconductive, Thick.
Resistances: Shock (75%), Blade (x1.5 AR), Arrows (x2 AR).
Weaknesses: Fire (25%), Frost (25%), Blunt (x0.75 AR).

Iron: Metal, Thick.
Resistances: Blades (x2.25 AR), Arrows (x3 AR).
Weaknesses: Shock (25%).

Steel: Fur/Metal, Thick.
Resistances: Frost (50%), Blade (x2.25 AR), Arrows (x1.5 AR).
Weaknesses: Shock (25%).

Dwarven: Metal, Deep.
Resistances: Blade (x1.5 AR), Axes (x1.5 AR), Blunt (x2 AR), Arrows (x1.5 AR).
Weaknesses: Shock (25%).

Ebony: Nonconductive, Deep.
Resistances: Shock (75%), Axes (x1.5 AR), Blunt (x1.5 AR).
Weaknesses: Fire (25%), Frost (25%).

Technical Information

Installation, and Uninstallation
Install through your mod manager of choice. To uninstall just remove the mod in your manager, very likely to be safe, but no guarantees.

Requirements
SKSE, SPID and KID.

Performance Impact
None.

Compatibility
KYE Redux - Armors is broadly compatible and there won't be any conflicts as it doesn't edit any vanilla records. Armors are recognized according to their armor material keyword, so if a mod added armor lacks such a keyword it will not be affected by KYE. Similarly, if a mod added armor has a vanilla keyword, KYE will treat it just like the vanilla armor with that keyword which may or may not be desirable depending on the look of the armor. For increased compatibility you should use the patcher version of KYE instead, although there is an expansion KID file for Immersive Armors in the optional downloads.

Comparison with KYE Original

KYE Redux - Armors

• Trivial to install, no patchers required.
• Configurable trait allocation.
• Affects all vanilla armors and many "vanilla-like" mod added armors, additional KID ini files can expand compatibility (see optional downloads).
• Get the creatures module for a creature resistances and weaknesses system.
  

KYE Original

• Installs through zEdit or synthesis patchers.
• Configurable trait allocation and effect intensity.
• Affects all vanilla armors and most mod added armors.
• Affects creatures too.
  

Synergistic mods

Know Your Enemy overhauls enemy defenses, but you'll probably want an enemy offense mod too. Skyrim Revamped - Complete Enemy Overhaul, Rogues 'n' Raiders and Draugr Upgrades and Improvements are all great options.

KYE favors breadth, but my character building mods Master of One, Legacy and Curse of the Firmament all favor specialization. Put them together and you get a fun challenge.

KYE gives you more reason to carry around multiple weapons, so why not show them off with a mod like AllGUD? You can also get a greater variety of weapons with a mod like heavy armory.

My other mods

Building Your Character - diverse and fun builds with strengths and weaknesses
Master of One - A perk overhaul that transforms perks from generic character progression into a means to craft unique and specialized builds.
Curse of the Firmament - A standing stones overhaul that emphasizes tough choices.
Legacy - A race overhaul that bring strengths and weaknesses to each race.
Acolyte - A progressive-yet-unobtrusive religion overhaul with a long path to divinity.

Enemies and Combat - challenging, varied and fair combat
Know Your Enemy (armor module, patcher version) - A resistance and weakness overhaul for enemies and armors.
Know Your Enemy 2 (armor module, integration patch) - An upgraded resistance overhaul: more damage types, more configuration, more polish.
NPC Stat Rescaler - A patcher that adjusts player and NPC stats for faster, fairer, and less spongy combat.
Enemy Releveler - A patcher that adjusts NPC levels to truly delevel the world.

Stats and stat growth - drawing out character growth to stave off premature godhood
Exhaustion - Incremental Fatigue - An ultra-lightweight injury/fatigue system.
Exercise - Incremental Growth - An add-on for Exhaustion that converts fatigue into stat growth.
Geometric Stat Growth - Stats grow by a configurable percentage on level up, instead of a fixed value.

Miscellanea
Challenging Spell Learning - Spell Tomes trigger a costly ritual you must pass to learn spells.
Trainers Galore - An expansion of the training system designed for "training only" leveling.
Pick Your Poison - An alchemical handbook to support strategic foraging.
Configurable Perks Per Level - An MCM to edit how many perk points you get on level up.
XP Editor - A patcher that adjusts xp gain and leveling.
Sightseer - Standing Stones - Guidebooks for the standing stones, collectibles to find, and a hidden quest to unite them.

Mod Lists
Thoughtful Skyrim - A small, gameplay-focussed modlist that rewards preparation and planning.

Acknowledgements

Thanks to everyone who helped with the original version of KYE. Thanks to powerofthree for SPID and KID.