What's the most impressive video game mod you've ever come across?

stalker anomaly, though i'm not sure if it qualifies as a mod or its own game.

Young me (and current me too) was always blown away by the Game Genie on the NES. Simple piece of tech that could do so much with so many games.

Caveat, I don't play a ton of modded games, but Dwarf Therapist for Dwarf Fortress is such a good mod. Makes the game playable, lol.

Fall from Heaven II. It's a fantasy themed overhaul mod for Civ IV. Has extraordinarily deep lore and unique game mechanics. I've never actually played the unmodded version of Civ IV. I only bought the game to play this mod.

On the Switch 1(or emulated), a Mario kart standalone mod call CTGP.

It's basically all the maps from all the MarioKarts and even a bunch of fan made maps on 1 game.

https://www.ctgpdx.com/

Super Mario 64 that added lugi as co-op

Counter Strike and Team Fortress. Both were Half Life mods when they started.

We played Quake World Team Fortress on the high school LAN. It blew my mind.
As well as DOTA (for Warcraft 3) and PUBG (Arma 2/DayZ mod).
I have a theory that the all the best multiplayer games do spawn from community efforts since they know better how to balance things.
Still remember discovering Half-Life as a kid because I was looking at the CS 1.6 folder my friend gave me, and I got curious about this "hl.exe" since the icon wasn't the CS one.
Remember the days of half life having three billion mods? Still haven't had the LAN with everybody where we play through them all.

Fallout UK

Cursed Halo.

I believe it was a passion project by one guy that took 5 or 10 years but holy shit it's a masterpiece.

No love for Fallout: London?

It's not just a Fallout 4 mod—it's full-blown AAA experience—done so well that I'd believe it was made by the New Vegas devs if I didn't already know. If you're tired of waiting for Bethesda to make the next FO game, just play this instead.

How well does it install on Linux?
- Tacking on cause id like to know as well. Last I checked it was VERY time consuming/if not impossible at the time.
Was looking for this answer, shame they released the DLC a month after I finally uninstalled FO4 because I needed the space lol.

Black mesa. Half life and half life 2 modder community is amazing.

To be fair, Garry's Mod is up there too.
The amount of customisation that one "small project" opened up in general, is astonishing.
Portal is basically a Half-Life 2 mod. It’s still got the fanboat asset. You can use the console to bind spawning a fanboat to an input, so there’s a speedrun category where you’re not allowed to use portals, but younare allowed to spam fanboats. Literally called fanboat%.
Speaking of Half-Life mods, Entropy Zero 2 is a solid game.
There’s also some great Portal 2 mods out there as well.
Endless hours playing Sven Co-Op. A few clips of my friends and my own earliest YouTube videos ended up in the NoClip documentary about Half Life!

Multiverse Mod for FTL

Its literally just a free sequel

Multiverse really does feal like early access FTL 2
Ooo I gotta look into this!

Vampire: The Masquerade - Bloodlines Unofficial Patch by Wesp5.

That game was already broken at launch, and has become more broken as operating systems advance. Furthermore, Activision shuttered Troika almost immediately after VTMB was released, so there has really never been any official support. But, Wesp5 has been working on the Unofficial Patch since shortly after the game came out in 2004.

It fixes the game to a completely playable state, which is a miracle for VTMB. He basically just finished the game for them.

Furthermore, there was some controversy over some of the changes that the patch started implementing, so he split the patch into two versions. You can download the True Patch, which fixes the game to a playable version of its release state, but Wesp5 also offers the Plus Patch, which restores all content cut from the game before release. He reimplemented character backgrounds, real-world weapon names, multiplayer, quests, locations, music, and the list goes on.

It's arguable if the Plus Patch actually represents the original vision of the creators, since we don't know why all of the content was cut. A good bit was cut for time, but there were some things that were dropped earlier in development. Either way, the Plus Patch went feature-complete last year, so what we have now is a fully working version of the game containing absolutely everything that was ever planned during its development.

I don't know if anything like that has happened before, and the only other thing like this that I can think of is the Saints Row 2 patch that IdolNinja was making before he died.

Mods that add stuff are great, but it's hard to beat a mod that lets you play one of the greats.

I love restored cut content, more often than not with these tragic projects it's literally because they ran out of time to polish the stuff, I also like to replay New Vegas with that mod that makes it a true open city, that was impossible since the 360 and PS3 couldn't handle it.
I can think of another example with KOTOR 2, it also has one that restores the cut content fully, though I don't know if that was a buggy mess since I have yet to play it, it's called TSL Restored Content Mod.
- Man, all of these games we're talking about relate in some way to the OG Black Isle team. I think their development is just cursed.

There are a TON of legit and amazing S.T.A.L.K.E.R mods like Misery, but my favorite is Anomaly. The mod team took assets across the three original Stalker releases, took alpha/beta builds, and combined all of these with a ton of other mods to make an ultimate OG stalker trilogy playground that is open and full of immersive experiences. Almost to the point where you can randomize starting characters and basically never play the same game again with how the NPCs have full independent routines.

Of course this means that a random quest giver can totally just get zeroed out and die before you ever even meet them, but that's part of the experience lol.

Star Trek New Horizons for Stellaris. Best Star Trek game I've played.

For me personally it has to be certain rom hacks from before the era of decomps and creation kit style tools.

I was fairly active in the gen 3 Pokemon hacking scene on the pokecommunity forums back in the day. And hex editing and trial and error was one thing but real wizards were the ASM hackers that could completely out of the box stuff like adding in new move effects or character customisation functionality or day and night systems, to games that had none of these.

Those were actually the trailblazers that led to all the decomps we have today that have made it so easy.

Inigo in Skyrim. Fully voiced follower who is funnier, more interesting and more authentic than any companion I’ve had in the last decade of games.

Been playing since launch and never used him because I hate companions (they ruin stealth). Seriously reconsidering for the next playthrough
- He's terrific and I never had him affect stealth archer/mage gameplay.
I absolutely love Inigo. Every time I go back to Skyrim (once a year or so), that's always a requirement on the mod list. No matter what my roleplay is, what my build is, Inigo is the Dragonborn's companion, in my head cannon.
- I think I’m subconsciously holding back going back into Skyrim until Inigo V3 is released.

Mechwarrior Living Legends is a mod for crisis that builds a compltely new game ontop of it and had a thriving multiplayer community for many years (not sure how activity is these days)

Project Reality, a Battlefield 2 mod.

I think the Galactic Contention (Star Wars) mod for Squad looks very impressive, albeit I’ve never played it.

https://youtu.be/hl4m5HkRiUI

Surprised no one has said MyHouse.wad yet

Dragon Genitals for Monster Hunter World. Gave each monster either a realistic cloaca or an incredibly well-crafted dong, tailored to the individual style of each monster. The details were amazing, like a monster called Bagel Goose has a rock dick, but when he transforms into B-52 bomber mode he glows red hot with lava… and his cock does, too.

The cock physics were pretty on point too. Just the right amount of movement to convey erectness.

The ACE mods have single-handedly kept Arma 3 alive for over a decade. They add so much complexity to the game with so many options for customization by both mission makers and players. It's amazing to me how much difference the ACE modset makes to the game.

I used to play Arma 2, and yeah, ACE was soooo good, and really added so much depth to the game

Space Age for Factorio before their basically made it a full DLC for the game

That was a mod? It honestly feels like the finished version of what the game was meant to be
- Before the factorio: space age update, there was a mod with the name space exploration. It was a complete overhaul mod, and even tho I never played it myself I did watch a lot of videos about it and I agree with the above poster that it was basically a completely free dlc. It is different from the official update tho

Strawberry jam for celeste. It's a huge collaborative project that introduces 100+ levels (base game has 25) with a really wide range of difficulties, graphical styles, new mechanics, original music and ideas on par with the quality from the base game. Definitely a must play if you like 2d platformers

Multiplayer for GTA San Andreas was quite revolutionary at its time.

Omg I totally forgot about SAMP. I spent so much time on there when I was young. Still remember v2 where there was so much lag being in a car together was so shitty but it was the best experience ever.
It blew my mind. I'm not a coder, so I have no idea how they did it.
- I don't know about San Andreas, but the GTA III co op mod was something pretty special. It took the other players coordinates and assigned them to your last vehicle, which didn't despawn.
  There were no on foot player characters, but you could drive around together in a game with absolutely no multiplayer or online elements at all.
Thousands of hours on an rp server early on in samp
- Same. Started with MTA and later moved to SAMP. Played on the same freeroam/rp server for years - even met one of the guys irl even though they were from a different country.

Withers big naturals

"The Last Days" for Mount & Blade. Intro

Mount & Blade was a medieval combat simulator where you're a wandering mercenary in a war torn region. The gameplay was somewhat innovative when it came out (originally 2008), but as far as story and setting, it was kinda meh. But the great thing about it were the mods, and by far the best mod was "The Last Days," a total conversion mod that lifted all the mechanics but put it in The Lord of the Rings.

These nerds put so much detail into that mod, it was incredible. I didn't know half the factions existed. The map goes beyond Gondor and Rohan and even Rivendell, it goes all the way out to the goblins of Mt. Gundabad fighting against the men of Dale. Each location has tons of detail, some of them are truly massive, and they pushed the limits of the base game with trolls and giant spiders and things like that. Each individual faction has their own faction strength, so you have to think strategically about where to reinforce. The differences between how each factions' units fight on the battlefield is more emphasized, and tbh the combat is a bit better balanced.

It really hit the nail on the head of what to do with the game engine, and then put real passion, creativity, and effort into making it work (seriously, the last update was in 2017, new stuff was being added after nearly a decade. And there's comments on the page I linked as recently as 10 days ago, so people are still playing it). Next to it, the base game feels a bit more like a proof of concept. The open world nature of the game really allows you to take in the setting and experience the story from a different perspective, rather than following the heroes from the books. It really made the setting come alive in a way I haven't found in really any other LotR game (although I'm not super into the setting and haven't played a ton of them).

The mod was for the original game at first but it update when they put out the sequel, Mount & Blade: Warband, so if anyone decides to check it out, get that one rather than the original.

My favorite m&b mod is Nova Aetus. Adds so much new stuff to the game. Custom troops, greatly expanded city building, and statecraft, religions, non battle locations outside of fiefs. Hidden loot and side quests. Colonies. If you are looking for a mostly mechanics mid that expands the game into a much more complex game, this is what I think is the best, although some other mods do story and setting better.

Otis_inf's camera tools. Blows away any in-game photo mode. No restrictions on movement at all, can pause or frame-advance the game, there's even a camera rails system I haven't fucked with yet.

Since someone already mentioned Fallout London, then I'll recommend Shutoko Revival Project for Asseto Corsa, a full blown open map in the speedways of japan with online support and even functioning traffic so the illegal racing isn't a breeze.

Hell yeah, I drove literally thousands of miles on those tracks in VR during Covid. Miss my little DIY sim rig so much. :(
- What happened to your rig?

There are quite a few honestly. Team Fortress and DayZ are obvious examples, I also quite liked Natural Selection.

Came here to say Natural Selection.
I would've picked DayZ mod as well but I really only got into it after the standalone version. It's still unlike any other game though.

Now I'm interested.

DSfix

Single-handedly made an awful PC port playable.

And watchdog making the cheating problem in multiplayer as close to solved as possible.

A Link to the Past/Super Metroid combo randomizer. Both games smooshed into a single ROM, with certain doors taking you from one to the other. Item pools are then shuffled together, sending you on a big scavenger hunt to find Metroid items in Hyrule so that you can explore Zebes to find Zelda items so that you can explore Hyrule.

Unfortunately it's somewhat lopsided due to how much bigger ALttP is than SM, but the technical novelty of it is amazing and worth a playthrough.

Gekokujo mount and blade.

They practically rewrote the game from scratch. There is a story-mode.

There was also a minecraft mod that functional programmimg based magic system but it was interesting more than impressive.

Elden ring seamless coop. I can't believe that such a small file could create such a better experience in the game.

Simbin's GTR2002 was an amazing mod of EA's F1 game. Great online racing and the added hotlap ranking from Find the Limit.

Many hours invested and IRC friends made. Got to race Gregor Huttu and had some of his setups ;)

Witchery for Minecraft. Start out, building your altar room, find as many unique living things as possible and put them within 100 blocks of your altar. Mid game, make sleeping tonics to visit the spirit realm and try not to die from nightmares. Create voodoo dolls, and other nice high level gear, craft some powerful pvp oriented spells. Late game create a ritual room to summon demons to trade with. Don't forget your protection circles because they move really fast and kill you almost instantly. Late game, become a vampire or werewolf or hybrid. Become nearly invincible outside of fire and sunlight.

Allowing you to collect all three triforce pieces in Ocarina of Time using arbitrary code execution.

Oh that's neat. I remember someone just saying "Cut out 3 yellow triangles, tape them to the TV, and have Link jump and get them." Lol!
- If you're curious, here's the setup and execution: https://youtu.be/2x_pqyrf9lA?t=706
  And the end result: https://youtu.be/2x_pqyrf9lA?t=2815

In terms of actual impact, a Fallout: New Vegas mod named Tale of Two Wastelands that takes a Fallout 3 copy and brings all of it into the Fallout: New Vegas world.

The mod makers didn't create the great bulk of the content, made a converter, but it amounts to a new experience with an AAA-game level of content addition.

Does make me wonder about other mods that can leverage pre-existing work. Cataclysm: Dark Days Ahead had a mod where someone imported a real life map of Massachusetts, for example. Some flight sims can do similar stuff.

Does the flight sim in Excel count? If yes, then that.

Otherwise, Day of Defeat (Steam mod). Still somewhat peeved that it never got the same recognition as CS.

Amen, Day of Defeat LAN parties were the best.

Princes of Darkness for Crusader Kings 3

Midian XL for Diablo 2

Expanded Stardew Valley! So much added stuff!

Rounding out my top three for Stardew are the pause and teleport mods
Came here for this!

Excessive Plus, a Quake 3 Arena mod

It's a mod where the weapons are extra powerful. Making for some interesting physics like using the weapons for jumping and one shot kills. Even with all the madness of super weapons, it had great gameplay and competiveness.

The community lost the steam and now there aren't many players last time I checked which is too bad because it was a great mod.

A movie with the mod: https://youtu.be/-qIvgdDznb8

X-Com and X-Com 2 Long War mods. Essentially the games at their full potential.

That reminds me, It's almost time for another playthrough i think.

Doom: Infinite is pretty cool. It turns it into a roguelike. It’s amazing as is, and is still in beta.

Space Exploration for Factorio. My dude built a huge mod for free, then was hired by the devs to desogn the paid sequel, Factorio 2, and although large and great its still smaller and less complex then the mod.

Krasstorio 2 as well. Not as complex, but just as good and the sprites were better than the base game.

Fall from Heaven 2 (overhaul mod for Civ4) would've been top pick until this year, now it's Enderal (even calling it an overhaul is selling it short, it's a whole new game built on the Skyrim engine).

Mekanism, an extensive tech mod for Minecraft that could quite happily be its own game.

I used to build my own modpack with Mekanism as the core mod. I simply love the Atomic Disassembler!

Pokemon unbound. Its a completely new game.

Can't recall the name but there was a Halo PC mod which was an entire fan made campaign.

Black Mesa

People who improve Bethesda's in game menus are awesome.

Half-Life: Firearms was sick back in the day.

Doom 3 OpenCoop. There's a few mods that convert the single player campaign into online co-op. At the time the competition was Last Man Standing, but I liked how vanilla OpenCoop was. There's better mods now, and OpenCoop never left Alpha versions. Although the only game breaking bug is with the first teleporter sequence which kicked all clients from the server. Easy enough to skip that segment.

It's a bit of a scripting nightmare since the game uses so many floor triggers for events never intended for multiple players. That's what impresses me about the mods.

That or The Dark Mod which is now a Standalone freeware title using idTech 4 engine to make a fan sequel to the classic Looking Glass Thief games. There's a TON of fan made high effort maps to play on.

I remember playing zombie master, a half life 2 mod on a lan party and being blown away by the mechanics. Also ,,the hidden,, was a new experience for me.

In zombiemaster one player plays against the rest and has a well... Real time strategy layout and spawns and controls different kind of zombies . The other players have to complete tasks and survive.

In ,,the hidden,, one player controls a almost invisible super strong rouge experimental super soldier against the special forces of iris .

Shrek mod for Left 4 dead 2😂

the multiplayer mod for BOTW

What?! There's a multiplayer mod for the wii u zelda?!
About that game, I replayed it with a Linkle total conversion that even edited the script to reference you were a girl now.
- yeah, you use cemu to play

Cataclysm: Darker Days Ahead.

Daily pull requests for over two decades on an open source project

Immersive cursedness

A minecraft server side mod that lets unmodded clients see through nether portals somehow

Team Fortress and Team Fortress Classic.

That's true. I don't know if the original TF was definitely the first game in the "class based team capture-the-flag" genre, but it certainly very early and influential.
considers
In the same vein, I've never played it, but maybe the original Defense of the Ancients, which I understand spawned the MOBA genre.
Not that many genres that are created by mods.

The entire OAR for Fallout 4:

Outcasts and Remnants

Fusion City Rising

Depravity

Project Valkyrie

I came across the Star Wars Helldivers mod. It’s basically Battlefront 3 but man it looks cool

The Vanilla Expanded mod set for Rimworld

Entropy: Zero 2 For HL2 was awesome

Command & conquer Generals Zero hour, Shockwave.

It's lesser-known, but the Battletech Advanced 3062 mod for Battletech from Harebrained Schemes is incredible. It adds so much it's almost an entirely new game (but still Battletech).

RogueTech for battle tech is amazing. Hundreds of hours into it.

GregTech. You need to be special to make the game this complex, and I am more for playing it.

Gregtech: we looked at all the wild stuff being done by other mods and thought "yes but what if tedium as well?"
Plus GTNH has a banger for a menu song
- I like playing on Monifactory. Nice worldgen theme and reduced earlygame grind making you focus on machines immediately.

I've never played it myself, but Gary's Mod was all the rage back in the day.

I was always astounded by hl2 mods.

There was one in particular that I really liked but it always crashed on me when I got even a little far in it. You spawn in a hotel and have to get away from the combine or something. I don't remember what it was called. But I really liked the idea of it.

If you haven't played Divinity Original Sin 2 with the Epic Encounters mod, you haven't experienced the game to its fullest potential. Give it a try if you already love DOS2 and would've liked to see more! 🙏

Enderal

My partner doesn't like skyrim but loves Enderal

Synergies for Torchlight II. It's like four extra games.

The "Vanilla: Expanded" series of mods for Rimworld adds an almost unbelievable number of new mechanics, almost all of which are intercompatible with most other popular mods. It's truly impressive how empty the default game feels after you play with mods for a while.

And if you limit it to just one single mod, I'd say "Save Our Ship 2" should get the Rimworld modding crown. IIRC Tynan himself reacted with amazement at how that had managed to add so many new mechanics to the game.

Action Half-Life was pretty great.

Lights. Camera. Action!

I forgot the names but there are a few amazing X-COM / UFO / Terror from the deep mods!

First thing that came to my mind: OreSpawn

Too bad that the creator went crazy

or he already was...

Yes, orespawn. that sure was something, probably was crazy all along. I am reminded of certain Skyrim modders when I think of orespawn

Hearthstone Access Community Version: https://hearthstoneaccess.com/

Patches full screen reader access into the game, despite no modding API or developer support, and makes it feel like it was natively there from the start. And is usually updated within 1-2 hours of Hearthstone getting a new version.

There are similar addons for Stardew, Slay The Spire, and Factorio. But I consider those less impressive as the game offers APIs for them to use.

Enderal was already mentioned so I'll say Project Brutality

It turns ol' Doom into a totally new (and so over the top that you can't help but love it) game

I really liked the Custom Maps in Warcraft 3 online play. I used to play Hero Line Wars, Mauls and TDs, Dota, Legion TD among other amazing community made maps

The New Order: The Last Days of Europe for Hearts of Iron 4

Considering how opaque the game was for modding, I'd argue Hearts of Iron 3 BlackIce is the more impressive achievement

Keep chunks loaded on Dinkum was pretty great since it allowed my auto mods to keep running while I was in the mines.

There was a mod for original half life called "Earth's special forces" and it had a variety of characters such as spider man, Goku, mega man, spawn, batman, superman, etc... it was super fun to Webb sling around the map or fly around or shoot kameha mehas.