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Single-player games you can play together with mods

58 games Steam lists as single-player have a community mod that adds co-op or multiplayer, and 19 multiplayer games have a mod that changes how you play them together. Every mod here was checked on 2026-09-09: the link works, the project is alive, and the status column says honestly whether it runs on the current game version (49 of 77 do). None of them are made or endorsed by the games' publishers.

Modded multiplayer is a huge part of how people actually play together now — Skyrim Together, Nitrox for Subnautica and BeamMP for BeamNG.drive each have millions of downloads, and every big single-player release now gets a co-op mod within months (Hogwarts Legacy, Clair Obscur, Silksong, Megabonk). Steam's own "games we both own" view will never show these as playable together, because the store still calls them single-player. Ready Up counts them: when you compare two libraries, mod-enabled games appear with a Via mod badge and a link to the mod, and one filter hides them if that isn't your thing. The rules for this list: free to use (one exception is marked), an official page you can download from, and a project that still answers to its users. Mods marked Beta are playable but rough; Old build only means you'll need an older version of the game from Steam's beta branches, or the project has gone quiet.

Which of these do you and a friend both own?Free, no login — uses public Steam profiles.

Mods that add multiplayer to single-player games (58)

GameModModesPlayersStatusYou need
Geometry Dash
Rhythm & music · 93% positive on Steam (429,921 reviews)
Globed
Real-time multiplayer for Geometry Dash: play any level with friends visible, with voice and text chat and private rooms.
co-opservers (public rooms)MaintainedGeode mod loader; PC, Android and macOS
Clair Obscur: Expedition 33
Party & tactical RPG · 96% positive on Steam (111,032 reviews)
Expedition 33 Co-op
Turn-based fights become a table for three: each player takes their own Expeditioner. Local only, but Remote Play carries it online.
co-op2–3 (local; works over Steam Remote Play)BetaSame PC or Remote Play Together via RemotePlayWhatever; controllers
Cyberpunk 2077
Open world adventure · 84% positive on Steam (844,921 reviews)
CyberpunkMP
Early and experimental — free roam Night City together, no synced story. Expect breakage after patches.
co-op2+BetaLatest game version; mod loader per the README
The Elder Scrolls V: Skyrim Special Edition
RPG · 92% positive on Steam (337,058 reviews)
Skyrim Together Reborn
The famous one: quests, dungeons and dragons with up to seven friends. Not every quest syncs perfectly; the team's wiki lists what does.
co-op2–8MaintainedSpecial or Anniversary Edition on Steam; one player hosts
The Sims™ 4
Farming & life sim · 87% positive on Steam (170,727 reviews)
Sims 4 Multiplayer (S4MP) · SimSync
Real-time shared households: build, cook, set fires and earn Simoleons together. SimSync is the other well-kept option.
co-op2–12MaintainedFree mod + launcher; one host; PC and Mac
RimWorld
Builder & management · 98% positive on Steam (210,517 reviews)
RimWorld Multiplayer
Run a colony together in real time; compatible with most popular mods when everyone has the same list.
co-op2–8MaintainedSteam Workshop; the host owns the save
Balatro
Cards & tabletop · 98% positive on Steam (153,566 reviews)
Balatro Multiplayer
Head-to-head runs with an "Attrition" ruleset — the first player to fail an ante loses lives.
PvP2MaintainedLovely mod loader; Steamodded
BeamNG.drive
Vehicle sandbox · 97% positive on Steam (322,278 reviews)
BeamMP · KissMP
The reason most people play BeamNG with friends: free launcher, community servers, mod support and voice chat. KissMP is the lighter alternative.
co-op + PvPservers (dozens per server)MaintainedBeamMP launcher; a free account
Slay the Spire
Cards & tabletop · 98% positive on Steam (182,277 reviews)
Together in Spire
Co-op climbs where every player fights the same encounters, plus a race mode.
co-op + PvP2–10MaintainedSteam Workshop; ModTheSpire
Cities: Skylines
Builder & management · 93% positive on Steam (275,770 reviews)
Cities: Skylines Multiplayer (CSM)
Build one city together; both players get the same tools. Cities: Skylines II is not supported.
co-op2+ (one host)MaintainedCities: Skylines 1; Workshop or manual install; port forwarding or Steam friends
Sekiro™: Shadows Die Twice - GOTY Edition
Souls-like co-op · 95% positive on Steam (322,234 reviews)
Sekiro Online
Community co-op and invasions for Sekiro; works when versions line up, breaks when they don't.
co-op + PvP2+BetaNexus Mods; check the mod version matches the game version
Oxygen Not Included
Builder & management · 97% positive on Steam (128,390 reviews)
Oxygen Not Included Multiplayer
Shares one colony between players. Playable and improving, but expect desyncs on big bases.
co-op2+BetaOne host; Steam or direct connection
Hogwarts Legacy
RPG · 90% positive on Steam (321,395 reviews)
HogWarp
Roam Hogwarts with friends, spells and all, from the Skyrim Together team. Beta: the world is shared, the story is not.
co-op2–10BetaFree; Nexus Mods download; one player hosts
Hollow Knight
Co-op platformer · 97% positive on Steam (415,946 reviews)
Hollow Knight Multiplayer (HKMP)
See each other in Hallownest, fight bosses together, optional PvP add-on. Mature and well maintained.
co-op + PvPservers (Steam lobbies)MaintainedHollow Knight Modding API; everyone installs the mod
Kenshi
RPG · 95% positive on Steam (98,135 reviews)
KenshiCoop
Experimental two-player co-op: each player runs their own squad in one persistent world. Ambitious and actively developed; expect rough edges.
co-op2BetaOne host; the host's save is the shared world
Fallout: New Vegas
RPG · 96% positive on Steam (227,700 reviews)
NV:MP
Community multiplayer for New Vegas, maintained since 2015 by a small team. Free roam with friends rather than a synced main quest.
co-op + PvPserversBetaWabbajack installer from the project site; Steam copy of the game
Resident Evil 4
Classic & campaign shooter · 98% positive on Steam (181,708 reviews)
RE4 Remake Multiplayer
Beta co-op through the 2023 remake: enemies, doors, switches and story events sync. Designed for one Leon, so expect oddities.
co-op2BetaNexus Mods; both players install; one hosts
Subnautica
Sci-fi survival · 97% positive on Steam (313,707 reviews)
Nitrox
Open-source co-op with over three million downloads; the ocean, bases and story sync well for a small crew.
co-op2–100 (best with 5 or fewer)MaintainedNitrox launcher (Windows/Linux); one player hosts or runs a server
ULTRAKILL
Hero & arena shooter · 98% positive on Steam (169,751 reviews)
Jaket
Co-op through the campaign or PvP in Steam lobbies, with emotes and chat. Hundreds of thousands of downloads and frequent updates.
co-op + PvPSteam lobbies (up to 5 teams)MaintainedBepInEx; everyone installs the mod
Hades
Co-op roguelike · 98% positive on Steam (279,741 reviews)
Hades Co-op
Two players fight through the Underworld with minimal gameplay changes — one runs Zagreus, the other a second fighter.
co-op2 (local; works over Steam Remote Play)MaintainedMod installer; two controllers, or Remote Play Together / Parsec for online
Timberborn
Builder & management · 96% positive on Steam (31,678 reviews)
Beaver Buddies
Early two-player co-op for the beaver city builder; working, actively developed, still early.
co-op2Betamod.io install; host needs port forwarding or a VPN like Hamachi
The Long Dark
Survival craft · 90% positive on Steam (112,575 reviews)
SkyCoop
Survive the quiet apocalypse together, but only on an older build of the game until the "Reborn" branch of the mod is ready.
co-op2+Old build onlyMelonLoader; The Long Dark 2.01–2.02 via Steam's beta branches — the current game version is not supported yet
Dyson Sphere Program
Factory & automation · 98% positive on Steam (85,088 reviews)
Nebula
Co-op factory building across the whole star cluster; keeps up with game updates well.
co-op2+ (one host)MaintainedBepInEx mod loader
Half-Life 2
Sci-fi shooter · 98% positive on Steam (245,627 reviews)
Synergy
Half-Life 2, Episode One and Episode Two in co-op with balanced enemy spawns.
co-opserversMaintainedFree on Steam; needs Half-Life 2 (and the episodes for their campaigns)
Kerbal Space Program
Space sandbox · 95% positive on Steam (127,162 reviews)
Luna Multiplayer (LMP) · DMP
A shared space program with time-warp syncing. DMP is the older alternative.
co-opservers (small groups)MaintainedKSP 1 only; a hosted server, or one player runs it
Noita
Co-op roguelike · 95% positive on Steam (78,477 reviews)
Noita Entangled Worlds · Noita Together
True co-op in one world — the mod rewrites Noita's physics sync so wands, enemies and the pixels themselves are shared. Noita Together is the older "parallel runs" approach.
co-op2+ (one host)MaintainedIts own launcher; everyone needs the game
Celeste
Co-op platformer · 97% positive on Steam (120,602 reviews)
CelesteNet
Ghost-style co-op: climb the mountain with dozens of other players visible, no collision, chat built in.
co-opserversMaintainedEverest mod loader
TCG Card Shop Simulator
Builder & management · 97% positive on Steam (39,499 reviews)
CardShopCoop
Run one card shop together — stock, sell and rip packs. New and actively developed.
co-op2+BetaOne host; BepInEx
Slime Rancher
Farming & life sim · 98% positive on Steam (138,097 reviews)
SRMP – Slime Rancher Multiplayer
Ranch together on one map. Last updated early 2024 and not free, so check it matches your game version first.
co-opup to 16Old build onlyPaid mod on itch.io; a free community build lives on GitHub (srmp-public)
My Summer Car
Vehicle sandbox · 95% positive on Steam (91,394 reviews)
My Summer Car Online (MSCO)
Wrench on the Satsuma with friends in one shared Finland. Community-run and in beta — read the site's setup guide.
co-op2+ (one host)BetaFree launcher from the project site
NieR:Automata™
Action RPG & dungeon crawler · 87% positive on Steam (140,169 reviews)
AutomataMP · YoRHa Network (PvP)
Two-player co-op through NieR:Automata — the important parts sync, there is no lobby system. YoRHa Network adds online PvP instead.
co-op2BetaLatest game version; both players install the mod
Outer Wilds
Co-op action · 96% positive on Steam (84,488 reviews)
Quantum Space Buddies
Explore the solar system together in one ship; the time loop resets for everyone at once. One of the best-made co-op mods anywhere.
co-op2+ (small groups)MaintainedOuter Wilds Mod Manager; everyone needs the same DLC state
Just Cause™ 3
Open world adventure · 84% positive on Steam (122,161 reviews)
JC3:MP
Sandbox multiplayer with community servers. Development ended; it still runs with a patch, and a few servers remain.
co-op + PvPserversOld build onlyFree on Steam; needs Just Cause 3; Windows 11 24H2 needs a community patch
Subnautica: Below Zero
Sci-fi survival · 91% positive on Steam (96,660 reviews)
Subnautica: Below Zero Multiplayer
A one-developer co-op mod for Below Zero (Nitrox does not cover it). Full release in 2025, still rougher than Nitrox.
co-op2+BetaWindows only; one player hosts
Ravenfield
Tactical & milsim · 97% positive on Steam (73,605 reviews)
RavenM
Battlefield-style bot battles with friends instead of alone — host through Steam, mods and maps sync.
co-op + PvPSteam lobbiesMaintainedEveryone installs the mod; lobbies through Steam (no port forwarding)
Batman: Arkham Asylum Game of the Year Edition
Action-adventure · 96% positive on Steam (73,651 reviews)
Arkham Asylum Local Co-op
A clever local co-op hack rather than native co-op — two players share the asylum.
co-op2 (local)BetaTwo controllers on one PC (or Remote Play Together)
Grand Theft Auto: San Andreas
Crime & open world · 92% positive on Steam (82,629 reviews)
Multi Theft Auto: San Andreas · open.mp
Twenty years of roleplay, racing and deathmatch servers on the 2004 classic. open.mp (the SA-MP successor) is the other big scene.
co-op + PvPservers (hundreds per server)MaintainedMTA client; the classic Steam copy of San Andreas
Blasphemous
Co-op platformer · 90% positive on Steam (51,484 reviews)
Blasphemous Multiplayer
See each other in Cvstodia and share items, stats and progress — a companion rather than a full co-op campaign.
co-op2+MaintainedBlasphemous Mod Installer
The Elder Scrolls III: Morrowind® Game of the Year Edition
RPG · 95% positive on Steam (26,384 reviews)
TES3MP
Full Morrowind co-op on the open-source engine, with public servers and scripting.
co-op + PvPserversMaintainedRuns on the OpenMW engine (free); Morrowind + expansions from Steam
DREDGE
Hunting & fishing · 96% positive on Steam (43,966 reviews)
Cosmic Horror Fishing Buddies
Fish the same haunted sea together; most events sync, a few still don't.
co-op2+BetaDredge Mod Manager
Getting Over It with Bennett Foddy
Co-op platformer · 82% positive on Steam (77,003 reviews)
Oxide MP
Lose your mind together: other players' cauldrons appear on the same mountain. Exactly as funny as it sounds.
co-op2+MaintainedEveryone installs the mod; one hosts or joins a server
Gothic II: Gold Edition
RPG · 94% positive on Steam (15,507 reviews)
Gothic 2 Online (G2O)
Roleplay and co-op servers for Gothic II, maintained for over a decade.
co-op + PvPserversMaintainedG2O client; Gothic II Gold from Steam
Just Cause 2
Open world adventure · 91% positive on Steam (50,739 reviews)
JC2-MP
Free-standing multiplayer that scales to hundreds of players on one island; the campaign stays single-player.
co-op + PvPservers (hundreds)MaintainedFree on Steam; needs Just Cause 2
Tales of ARISE
Action RPG & dungeon crawler · 87% positive on Steam (34,782 reviews)
Tales of Arise Multiplayer
Each friend controls a party member in battle. The author calls it mostly feature-complete and "somewhat stable".
co-op2–4BetaOne host; mod loader per the README
Hot Dogs, Horseshoes & Hand Grenades
VR · 97% positive on Steam (22,104 reviews)
H3MP
Multiplayer for the VR gun-range sandbox: shared scenes, Take & Hold together, PvP if you want it.
co-op + PvPSteam lobbiesMaintainedr2modman / BepInEx; PC VR
Grand Theft Auto: Vice City
Crime & open world · 93% positive on Steam (29,276 reviews)
Vice City: Multiplayer (VC:MP)
Long-running multiplayer for Vice City with scripted servers.
co-op + PvPserversMaintainedVC:MP client; the classic Steam copy of Vice City
Half-Life 2: Episode Two
Sci-fi shooter · 97% positive on Steam (41,782 reviews)
Synergy
Episode Two in co-op through the free Synergy mod.
co-opserversMaintainedFree on Steam; needs Episode Two
Mirror's Edge™
Action-adventure · 88% positive on Steam (37,652 reviews)
Mirror's Edge Multiplayer
Parkour races and tag with other runners visible in the city. Works, but hasn't seen a release in a while.
co-op + PvP2+Old build onlyEveryone installs the mod
White Knuckle
Horror · 99% positive on Steam (3,034 reviews)
WKMultiMod
Climb and survive White Knuckle together — movement, enemies and world interactions sync, with team rules and lobbies.
co-op2+ (lobbies)BetaEveryone installs the mod
BONELAB
VR · 79% positive on Steam (16,281 reviews)
BONELAB Fusion
The definitive VR multiplayer mod: physics-synced avatars, lobbies over Steam, and a module system other mods build on. Updated all through 2026.
co-op + PvPSteam lobbiesMaintainedMelonLoader; PC VR and Quest
Half-Life 2: Episode One
Sci-fi shooter · 96% positive on Steam (31,822 reviews)
Synergy
Episode One in co-op through the free Synergy mod.
co-opserversMaintainedFree on Steam; needs Episode One
Darkwood
Horror · 95% positive on Steam (21,618 reviews)
Darkwood Co-op
Two-player online co-op through the campaign — world, enemies, weather and time sync. Alpha quality by the author's own label.
co-op2BetaNexus Mods; both players install; one hosts
Bomb Rush Cyberfunk
Action-adventure · 98% positive on Steam (13,387 reviews)
SlopCrew
Skate the same city as other players with chat and races — a shared-world layer over the single-player game.
co-opserversMaintainedBepInEx; a public or self-hosted server
RollerCoaster Tycoon® 2: Triple Thrill Pack
Builder & management · 89% positive on Steam (5,445 reviews)
OpenRCT2
The open-source re-implementation of RollerCoaster Tycoon 2 adds real multiplayer: build one park together on a server.
co-opserversMaintainedOpenRCT2 (free) plus your RCT2 files from Steam
TY the Tasmanian Tiger
Co-op platformer · 98% positive on Steam (2,596 reviews)
Mul-Ty-Player
Well-documented co-op for the Ty remaster from the game's modding community.
co-op2+MaintainedEveryone installs the mod; one hosts
Tomb Raider II (1997)
Action-adventure · 87% positive on Steam (2,306 reviews)
Tomb Raider II Multiplayer
Sixteen Laras in one level, with full sync and a PvP option — a labour of love for the original Tomb Raider II.
co-op + PvPup to 16Old build onlyThe 1997 game from Steam; everyone installs the mod
Hollow Knight: Silksong
Co-op platformer · not enough Steam reviews yet
SSMP (Silksong Multiplayer)
Early multiplayer for Silksong with lobbies, co-op and PvP. Moving fast — versions must match.
co-op + PvP2+ (Steam lobbies)BetaBepInEx; everyone installs the mod
Megabonk
Co-op roguelike · not enough Steam reviews yet
MegabonkTogether
Up to six players survive one run together; enemies, chests, shrines and progression sync. New and moving fast.
co-op2–6BetaEveryone installs the mod; peer-to-peer over Steam

Mods that change how multiplayer games are played (19)

These games already have multiplayer on Steam; the mod replaces or extends it — persistent co-op instead of summon signs, community servers instead of official ones, the single-player campaign in co-op.

GameModModesPlayersStatusYou need
Grand Theft Auto V Legacy
Crime & open world · 87% positive on Steam (1,990,556 reviews)
FiveM · RAGECOOP
Custom servers — roleplay, racing, minigames — that have nothing to do with GTA Online. RAGECOOP is the pick if you want the story missions in co-op.
co-op + PvPservers (up to thousands)MaintainedFiveM client; a legitimate copy of GTA V
Stardew Valley
Farming & life sim · 98% positive on Steam (886,195 reviews)
Stardew Valley (native co-op)
Co-op is built in; SMAPI mods work in multiplayer when every player has the same set.
co-op1–8MaintainedNothing — co-op is built in
Grand Theft Auto V Enhanced
Crime & open world · 69% positive on Steam (55,881 reviews)
FiveM
Custom roleplay, racing and minigame servers outside GTA Online.
co-op + PvPservers (up to thousands)MaintainedFiveM client; the Enhanced edition is supported
ELDEN RING
Action RPG & dungeon crawler · 93% positive on Steam (1,056,677 reviews)
Seamless Co-op
Persistent co-op through the whole game instead of the summon-per-area system. The gold standard of "the game has multiplayer but this is better".
co-op2–4MaintainedNexus Mods; everyone installs it; runs as a separate launcher so vanilla saves stay safe
Red Dead Redemption 2
Open world adventure · 92% positive on Steam (733,542 reviews)
RedM
Community roleplay servers alongside the official Red Dead Online.
co-op + PvPserversMaintainedRedM client (from the FiveM team)
Euro Truck Simulator 2
Driving & trucking sim · 97% positive on Steam (867,404 reviews)
TruckersMP
Massive shared-world convoys with traffic rules and events; the game's own Convoy mode tops out at 8.
co-opservers (thousands)MaintainedTruckersMP launcher + free account
Mount & Blade II: Bannerlord
Melee combat · 88% positive on Steam (264,391 reviews)
Bannerlord Together
The single-player campaign for two: each player runs their own party while towns, battles and diplomacy sync. The game's own multiplayer is battles only.
co-op2BetaSteam Workshop; one host
American Truck Simulator
Driving & trucking sim · 97% positive on Steam (175,287 reviews)
TruckersMP
The same shared-world trucking for American Truck Simulator.
co-opservers (thousands)MaintainedTruckersMP launcher + free account
DARK SOULS™ III
Souls-like co-op · 94% positive on Steam (413,775 reviews)
Seamless Co-op (Dark Souls III)
The whole of Dark Souls III as one uninterrupted co-op run, from the same author as the Elden Ring mod.
co-op2+MaintainedNexus Mods; everyone installs it
DARK SOULS™: REMASTERED
Souls-like co-op · 92% positive on Steam (129,299 reviews)
Seamless Co-op (Dark Souls Remastered)
From the Elden Ring Seamless Co-op author: no fog-wall kick-outs, no summon signs — start at the Asylum and finish the game together.
co-op2+MaintainedNexus Mods; everyone installs it
Grand Theft Auto IV: The Complete Edition
Crime & open world · 82% positive on Steam (175,184 reviews)
GTA Connected
One multiplayer client for GTA III, Vice City, San Andreas and IV — GTA IV lost its own online play when Games for Windows Live shut down.
co-op + PvPserversMaintainedGTA Connected client
Titanfall® 2
Competitive shooter · 95% positive on Steam (256,188 reviews)
Northstar
Community servers, mods and custom game modes that keep Titanfall 2 alive independently of the official servers.
co-op + PvPserversMaintainedNorthstar launcher; the game on Steam
Black Mesa
Sci-fi shooter · 95% positive on Steam (127,693 reviews)
SourceCoop
Plays the single-player campaign co-operatively on a Black Mesa server; the game only ships deathmatch on its own.
co-opserversMaintainedRuns on a Black Mesa dedicated server (SourceMod plugin)
Half-Life
Sci-fi shooter · 97% positive on Steam (148,221 reviews)
Sven Co-op
Twenty-five years old and still updated: the whole Half-Life campaign and hundreds of custom maps in co-op (the game itself only ships deathmatch).
co-opservers (up to 32)MaintainedFree on Steam; needs Half-Life
Rain World
Co-op platformer · 94% positive on Steam (42,277 reviews)
Rain Meadow
Online story co-op, arena and a peaceful "Meadow" mode with Steam matchmaking. The game's built-in Jolly Co-op is local only; this takes it online.
co-op + PvPsmall groups (arena takes more)MaintainedSteam Workshop; everyone installs it
S.T.A.L.K.E.R.: Call of Pripyat
Classic & campaign shooter · 96% positive on Steam (30,957 reviews)
X-Ray Multiplayer Extension (xrMPE)
Seven years of work turned Call of Pripyat into a co-op game: host a server and walk the Zone with three friends, plus its own PvP modes.
co-op + PvP2–4 in co-opMaintainedxrMPE launcher from the project site; Call of Pripyat on Steam
Battlefield 3™
Competitive shooter · 70% positive on Steam (15,360 reviews)
Venice Unleashed
Private dedicated servers, high tick rate and mods for Battlefield 3 — the way the community plays it now.
co-op + PvPserversMaintainedVU client from the project site; the game on Steam
Dark Messiah of Might & Magic
RPG · 91% positive on Steam (10,764 reviews)
Dark Messiah Co-op
The single-player campaign as a co-op adventure with shared saves and persistent skills — the game's own multiplayer is a separate arena mode.
co-op2+BetaModDB download; one host
DOOM 3
Sci-fi shooter · 89% positive on Steam (7,827 reviews)
OpenCoop
Four-player co-op through Doom 3, Resurrection of Evil and 42 custom maps. Old, but it still works.
co-op2–4Old build onlyDoom 3 (2004) from Steam; ModDB download

How to use this list

Everyone needs their own copy of the game on Steam; the mod is free (Slime Rancher's is the paid exception). Install the mod on every PC, then one player usually hosts. Check the mod's page for the game version it supports before an update night — modded multiplayer breaks when Steam auto-updates the game, which is why several projects ask you to pin a beta branch. Ready Up's library comparison shows which of these you and a friend both own, and the type hubs list every natively multiplayer game.

Corrections and new mods: see how to reach us. Mod names are trademarks of their authors; game names of their publishers.

Ready Up is a free tool: enter two Steam usernames and it lists the multiplayer games you both own, runs a bracket to pick one, and suggests new co-op games that fit how you both play. Ratings, tags and player counts from Steam and SteamSpy; page updated 2026-09-09. Powered by Steam — not affiliated with or endorsed by Valve Corporation or Microsoft. How the data works · Legal & privacy · All types · Game Pass