So before I went to sleep last night I laid down brainstorming, and here's my ideas of how I'd improve Skyrim to be what I'd see as a million times better- USING the Perk system, to ACTUALLY replace attributes, and ALSO doing a huge overhaul of how stamina works, as well as creating an Ocarina Of Time inspired night time to also make it feel a little bit more like a survival horror game.
Instead of attributes LITERALLY coming back, there'd be Perks, with several ranks, that function similarly enough to attributes that they are immersive.
Also instead of Skyrim/Oblivion's much easier to level combat skills, and Daggerfalls/Morrowinds miss system, attacks even regular attacks would drain stamina faster, and only raising skill with a weapon type would make the drain rate go down, lower stamina would cause severe damage penalties as well as speed penalties.
Stamina Overhaul: You do 99% less damage under 5 stamina, 100% less damage at 0 stamina, 90% less damage under 20 stamina, 80% less damage under 30 stamina, 75% less damage under 40 stamina, 30% less damage under 50 stamina, and 20% less damage under 80 stamina. Under 20 stamina your movement speed is slowed by 30%.
Even regular attacks drain stamina, and stamina from regular attacks drains MUCH MUCH MUCH FASTER than it did in any prior TES game- UNLESS YOUR weapon skills explained down below, decrease the stamina drain from attacking.
Stamina no longer increases carry weight, carry weight is now increased by "strength based perks", an alteration spell, and alteration perks... However for every 50 stamina you gain you move 10% faster, to a maximum of 100% added speed.
Starting carry weight overhaul: Carry weight now starts at 50 for Altmer and Bretons, 80 for Suthay-raht and Bosmer, 130 for Imperials, 150 for Dumner, Argonians, and Redguards, and 195 for Nords, Cathay Raht Khajiit, and Orcs.
Khajiit players on character creation, could choose the optional Cathay Raht trait- instead of the regular Suthay-raht visually they'd just be giant Suthay-raht Khajiit for ease of programming expenses and time, which would make simply make them as tall if not a bit taller than an Altmer, and would make them start out with 195 carry weight, they would also start out with less stamina however.
Starting Stamina Overhaul: 50 for Altmer and Bretons, 80 for Imperials, 90 for Nords, Cathay Raht and Orcs, 110 for Dumner, 130 for Redguards, 140 for Suthay-raht and Bosmer
Starting Health Overhaul: 80 For Altmer and Bosmer, 90 for Suthay-raht Khajiit and Bosmer, 100 for Imperials, 110 for Dumner, Argonians, and Redguards, 130 for Nords, Orcs, and Cathay Raht Khajiit.
Starting Magika Overhaul: 50 for Nords, Orcs, and Cathay Raht, 80 for Imperials, Suthay-raht Khajiit, Bosmer, and Redguards, 110 for Dumner, and Argonians, 130 for Bretons, 175 for Altmer.
Perks: Every perk listed would have 15 ranks to max them out, resulting in it taking more time to become that powerful than it did in Skyrim. With one perk point per level. These perks are all described as if they are at max level.
Luck based perk: Looking at Daggerfall and Morrowind- this is how I'd create a perk to replace the Luck stat.
Sneak Tree- Lucky Hands: Grants 40 extra stamina, Adds a 5% chance to slow combat when you're about to be hit, 10% easier lockpicking, 10% higher chance to succeed with enchants and potions, adds a 20% chance to find better loot, although you'll still never find glass, ebony, or daedric armor randomly.
Strength based perks...
Two-Handed-SkullCrusher: Now at max rank gives 150 extra carry weight, on TOP of it's old bonuses of ignoring armor. However, the carry weight bonus doesn't stack with Bone Breakers bonuses if you choose to fill out both the two handed and one handed tree. Now requires 15 perk points to max out. Also at max rank your regular attacks cost 90% less stamina, and power attacks with this weapon type costs 50% less stamina.
One Handed-Bone Breaker: Now at max rank gives 150 extra carry weight, on TOP of it's old bonuses of ignoring armor. However, the carry weight bonus doesn't stack with Skullcrushers bonuses if you choose to fill out both the two handed and one handed tree. Now requires 15 perk points to max out.
Block Tree-Strong Arm: Does everything Shield Wall does, as well as gives 150 extra carry weight. Now requires 15 perk points to max out.
Heavy Armor Tree-Juggernaut: Does everything Juggernaut already does as well as gives 150 extra carry weight. Now requires 15 perk points to max out.
If you max out all these Strength perks, you can get 450 extra carry weight, and even the Altmer and Bretons could get 500 maximum carry weight like the max carry weight in prior TES games with no spells or enchantments. Nords and Orcs would have higher max carry weight than in prior TES games.
Other melee perks...
Two Handed-Deep Wounds: All the same bonuses as before, also at max rank your regular attacks cost 90% less stamina, and power attacks with this weapon type costs 50% less stamina.
Two Handed-Limbsplitter: All the same bonuses as before, also at max rank your regular attacks cost 90% less stamina, and power attacks with this weapon type costs 50% less stamina.
One Handed-Hack And Slash: All the same bonuses as before, also at max rank your regular attacks cost 90% less stamina, and power attacks with this weapon type costs 50% less stamina.
One Handed-Bladesman: All the same bonuses as before, also at max rank your regular attacks cost 90% less stamina, and power attacks with this weapon type costs 50% less stamina.
Speed/Agility based perks below.
Light Armor-Lightning Reflexes: Replaces Deft Movement, now requires 15 perk points to max out, makes you move 40% faster, jump 30% higher, and gives a 40% chance to slow your enemy when you are about to be attacked. Now a truly powerful perk for the end of a perk tree... That also brings back the FEELING that speed and agility were SUPPOSED to provide in prior TES games. It also stacks with the speed bonus from Stamina, for a total of 140% faster movement speed.
Edit: Meant stacks with Stamina not Alteration.
Alteration Tree- Arcane Buoyancy: Replaces Master Alteration, and provides all the bonuses of Alteration, plus gives 150 extra carry weight, 50% faster swimming speed, and the ability to walk on water even in heavy armor.
Yep you can now get 650 carry weight as an Altmer or Breton if you combine this with all the strength perks or even more as an Orc or Nord... More than prior TES games- but 15 perk points is a lot, perks should be rewarding, low level survival should be an epic struggle outside of Story Mode, and you'd need to be very high level to max all these out. In a world in which magic can increase carry weight- DOESN'T it just make sense that a Battlemage type who is strong in both magical spells and body would be able to carry the most? I think so.
Also some new ideas of difficulty are inspired by Daggerfall, I had an idea for a few different difficulty modes.
Story Mode: About as easy as vanilla Skyim. Low stamina doesn't cause a damage or speed penalty, and all races start out with their weakest stats, INCLUDING carry weight at 100, unlike in Normal mode where Altmer for example start with a paltry 50 carry weight. Durability isn't a thing in this mode. Also the nocturnal undead I'll explain shortly are very weak cannon fodder- the nocturnal undead max out at level 10.
Also the nocturnal undead will only show up about 5 at a time and after killing them their respawn time is an 40 minutes.
Torches/light spells/night eye spells last for about 2 real time hours in this mode unless cancelled more details later.
Normal Mode: Pretty much exactly as I described- Like Skyrim with a more complicated Perk tree that requires more perk points to reach max potential, and stamina much much more important. The nocturnal undead are unleveled but only about level 15-20. Torches/light spells/night eye spells last about 1 hour real time.
Durability is a thing now, though instead of breaking weapons just become about 10% less effective with their damage range... So yes durability loss is a thing unlike Skyrim or Fallout 4, but it's way more mild of a downside than other Bethesda games.
Also the nocturnal undead will only show up about 10 at a time and after killing them their respawn time is at 20 minutes.
hardcoe Mode: Inspired by Daggerfall, an Exhaustion stat that doesn't exist in Normal mode. It's like a giant orange fatigue bar, drains much slower and it would have a huge stat number, like 2000-3000, and it doesn't help you do anything unlike the actual stamina bar- when it hits zero you die if you don't sleep in a safe place. The unscaled nocturnal undead now are level 25-30, or up to level 35 if you walk around without a torch or light spell or night eye. Also disease can now kill you, and so can stats being reduced to 0. Map click Fast Travel is disabled in this mode.
As a vampire the sun will damage your health as well. Ghosts, and Daedra become immune to normal weapons in this mode, vampires gain a 50% normal weapons resistance in this mode.
Weapons and armor at maximum wear and tear, don't break but they become 95% less effective, where the armor provides near zero protection, and weapons at this point do less damage than untrained hand to hand. Gold and arrows also have weight, and there's more pressure to use an in game banking system that turns gold into light weight paper money similar to Daggerfall. Sneak attacks no longer work on Undead, any divine characters or Daedra in hardcoe mode- because they don't have mortal vital organs you can hit with pin point accuracy.
Sneak attacks work on vampires but do half the bonus damage they'd normally do. Torches/light spells/night eye spells last about 30 minutes real time. The nocturnal undead will continue to respawn, and there can be as many as 15 or 20 around you, but if you kill all nearby nocturnal undead they will have a 10 minute respawn timer.
Nightmare Mode: Everything hardcoe Mode has, only NOW the weakest nocturnal undead are level 35, and the elite night monsters are level 50-90. Weapons and armor actually break. Also just like Daggerfall magical items and artifacts can't be repaired. As a vampire the sun will kill you much faster than in hardcoe Mode. Torches/light spells/night eye spells last about 15 minutes real time. This time the nocturnal undead will only have a 2 minute respawn timer, and this time show up in groups of 20.
New Darkness system: If you have no torch, night eye, or light spell and are in a dark place your attacks costing 60% more stamina... This is supposed to simulate visual impairment from low light levels resulting in clumsiness on your characters behalf.
New Scary Night Time System: If you are out at night, and not close to a city or town, you will encounter undead beings extremely similar in their mechanics to the Stalfos in Ocarina Of Time Zelda. They will come out at night and follow you around. They will be ghosts, zombies, skeletons, that kind of thing, and they'd be stronger than most enemies in the open world. The idea is a bit inspired by the Stalfos in Zelda, as well as some horror games where light can literally repel deadly enemies.
I partially got the idea when I saw a Skyrim mod that makes predators avoid you when you have a torch out.
Now as for torches and light spells and night eye and stuff? Well you see, if you carry around a torch or use a light spell it will prevent you from encountering super high level elite undead, and reduce the amount of undead enemies that spawn around you. Using torches and light spells would guarantee the amount of undead wandering the night are fewer, and that the elite undead don't show up, using Night Eye wouldn't guarantee they don't show up, but would have a 50% chance of reducing how many undead show up, and a 80% chance of preventing you from encountering elite undead whenever you load a new cell. Undead would also randomly spawn inside of caves, and mines that aren't watched over by a lawful town or city.
As for named NPCs? Named NPCs in cities would be safe from undead, named NPCs away from civilization would usually either use a well lit campfire, or hide inside of their houses at night to avoid the wandering undead. This would be set up carefully so the undead would be a threat to the player, but wouldn't kill named NPCs... Other than maybe a FEW named NPCs who exist solely to be killed by the undead to add to the horror and immersion factor.
Khajiit Night Eye, and Khajiit Climbing Bonus.
Climbing is enabled by default with no skill requirement, the higher your stamina the longer you can climb for, Khajiit climb 25% faster, Khajiit also gain a night eye power that can be toggled on or off that lasts forever, and because of this Khajiit actually have an advantage in climbing, as well as being a bit safer exploring at night time.
Nothing in the game will actually require you be a Khajiit to climb to the top, Khajiit will just have an easier time climbing and be more efficient at it.
Making use of Argonian Poison Resistance.
I'd also like to perhaps add in something like toxic swamps- where walking or swimming through them can provide short cuts to various areas, but they also rapidly damage your health unless you're an Argonian. Hence non-Argonians would have to take the long way around, or climb or jump over said swamps. If you're not an Argonian you can use Alchemy or Restoration spells to shield yourself but it costs magicka.
Later on in the game perhaps you can get a mount- not a horse this time that's slightly slower than a horse but also immune to being damaged by these swamps.
Anyhow... THIS is how I PERSONALLY would've designed Skyrim's Perk System, as well as Skyrim's Stamina, and what features I would've implemented into Skyrim if I were like the head developer, these are the types of things I wish there was a mod for exactly...
And these are also ideas I'd like to see in TES 6, especially if Attributes themselves are never coming back, at least a perk system, that I feel would have a much better replacement than Skyrim's perk system. Personally I like it when the undead walk around the world at night, it's just something I find cool, and I think it would've made the Draugr and undead in TES games a lot more scary if they roamed the world at night and were more powerful.
Maybe my math is a bit off for perfectly balancing things, but what I described is how I wish Skyrim was, and how I hope TES 6 will be.