It’s called “Requiem: The Oldschool Roleplaying Overhaul”, and from the sound of it, it is INTENSE, baby. It was crafted by Skyrim Nexus user Xarrian, who describes the mod’s goals thusly:
The main goals of this mod
1. Make the game experience deeper and more believable by adjusting about everything in a semi-realistic way suitable for fantasy worlds while keeping the mod as lorefriendly and immersive as possible
2. Make it more challenging
3. Make it more fun
4. Make it feel more like older titles (Arena, Daggerfall, Morrowind, Baldur’s Gate, Planescape: Torment, Gothic, Deus Ex; just to name a few of my inspirations)
5. Make it as simple, stable and bugfree as possible – No use of any script extending programs or other required third party utilities, only lightweight and safe scripts, no too performance eating tweaks!
6. Provide a lot of options/modularity so one can adjust the mod as one sees fit – from the weight of gold to overall difficulty! (The default settings of this mod may be “Hardcore”, as some people refer to it, but with a few options, it should be enjoyable for everyone!
The list of features is far too lengthy to re-create here, but the Requiem mod makes just about everything in the game more involved and difficult. Levels are now static, mid- and high-level enemies ruinously difficult, skills, perks and magic overhauled, there are a ton of new spells, and combat difficulty and enemy AI have been redone.
Blocking is essential. Not blocking in combat is almost like suicide if you don’t wear a second skin made of pure steel – as many enemies also have armour piercing attacks (like bears crushing you under their sheer body mass), even that might not save you from a painful death. But don’t even think about blocking when you’re not trained in it…
– All existing spells have been redone to suit the mod better (adjusted effects, changed some graphics, renamed for better sorting and much more) *
– Almost all spells now improve with a better spell school skill level *
– Spell costs will double when you only have a very small amount of stamina left
– Heavy armour increases magicka cost for all spells (up to incastability) – Ongoing Battlemages can get rid of this by investing in certain Heavy armour perks *
NPCs will yield in a more believable way. When they say it, they mean it! If left alive, they’ll be affected by a fear effect that will cause them to panically run away from you for quite some time – if you leave them, they might just disappear or become hostile after you return to the loaction after a long while.
Archers are now extremely deadly. Arrows are much faster, NPCs aim better, drawing a bow takes more time for untrained persons. A normal human will go down with one or two hits when not being armoured heavily – for a piece of wood and metal in your intestines isn’t something you just shrug off.
Running low on stamina during a fight is possibly the worst thing to happen with this mod: If you become hit by a spell, arrow or whatever sort of attack while your stamina is really low (absolute value), you will become staggered and won’t regenerate any stamina for some moments.
Wearing any heavy armour will render most thieving activities much harder or even impossible
There are dozens upon dozens of other tweaks — races will now have stat boosts like in past Elder Scrolls games, horses are entirely different… hell, just everything in the game is different.
If you’re looking to change Skyrim altogether and experience it fresh, go ahead and install this mod. I haven’t yet, but man… I think I’m going to. If anyone out there has this installed, pipe up; I’d love to hear how it is.