v0.8.2 betaSteam Next Fest: play the free demo 19 October to 26 October.MMOS launches on Steam on 11 December 2026. Play the free demo now.Wishlist on Steam →

Demo in Steam Next Fest · Full game 11 December 2026

The MMO simulator: build and run your own fantasy MMO

A single-player MMO simulator: design the world, classes and loot, then watch simulated adventurers play it, form guilds and chase rare drops.

Wishlist on SteamTry the free demo

Free demo on Steam and itch.io now. Full game on Steam 11 December 2026. Coming later to Google Play and the App Store.

Latest update · v0.8.2adventurers who hunt in bouts, fights that end in a kill, faction land that refuses rivals and faster Items and Professions windows.Read the patch notes
The twist

You're not the hero.
You run the whole game.

In other MMOs you log in and grind. In MMOS you sit on the other side of the screen. It's an MMO tycoon game: you build the dungeons, the economy and the flight paths, then simulated adventurers log in, form guilds and play it on their own.

It's RollerCoaster Tycoon meets World of Warcraft

Adventurers fighting mobs on an island server in MMOS
01

Build the world

Raise islands, shape the terrain, and place towns, docks, inns and graveyards. Every tile costs starting capital, so spend it well.

02

Open the servers

Simulated adventurers log in and play the MMO you built. They hunt, group up, craft and sail on their own.

03

Keep them subscribed

Check your stats, fix what's broken and give players a reason to stay. Bored players cancel. Happy ones bring friends.

You design all of it

The classes. The loot.
The dungeons. The quests.

MMOS gives you an editor for every system in the game. Create a class, lay out a dungeon, set the loot table, then watch adventurers use what you made.

How you build your own MMO, step by step
Free demo

Run your first server,
right now, for free.

The free MMOS demo runs in your browser or as a download. Build an island, place a town, open the servers and watch simulated adventurers move in. No sign-up needed.

Play the demo on Steam

Play fullscreen on your PC, or right here in the browser.

On your phone? Wishlist now, then play the demo on your PC.

Play the MMOS demo on itch.io

Like what you built? Wishlist the full game on Steam.

A party of adventurers clearing a dungeon on a live server in MMOS
Your world, your rules

Everything an MMO needs,
and you place all of it.

Towns, cities, docks, graveyards and spawners. Each building changes how your server plays. Place it from the toolbar and see how adventurers respond.

Adventurers grouping up and hunting mobs on an island server in MMOS

Place mobs and spawners

Hunting grounds give tanks, healers and DPS a reason to group up. You set the threat, aggro and respawn rates.

An archipelago of themed, level-banded islands linked by docks in MMOS

Shape the land

Raise land, set coastlines, plant forests and build an archipelago of themed islands, each one set to its own level range.

Keep them coming back

Give them a reason
to log back in.

Mounts to save up for, skies to open and a calendar that keeps moving. Each one gives adventurers another reason to stay subscribed.

An adventurer on a drake mount beside a party fighting on the coast in MMOS

Stables, vendors and rare drops

Stable vendors open in your cities and rare mounts drop from bosses. Adventurers collect them and ride the fastest, rarest one they own.

An adventurer crossing the open sea on a flying mount in MMOS

Then open up the sky

Flying mounts are a late unlock. Flyers cross open water, so your far islands stop being a long boat ride away.

The in-game event calendar in MMOS, with Winterfest and a Community Day coming up

A week that keeps ticking

Your world runs on a weekly cycle: busy weekends, holiday seasons and a reset day you choose. Fund your own events and watch logins climb, or watch a flop cost you.

Get your name in the game

Join the Discord for news and updates. Post your in-game name in #names and look for your character in the simulation when the servers go live.

Join the Discord
The guild rankings and a guild roster in MMOS
10 Hz live sim1,000s of agents4× time control

A whole world, simulated.

Every adventurer has its own archetype and goals. They group up, trade, join guilds and decide whether your world is worth the subscription.

The economy is the game

Run the numbers,
not the raids.

A player-driven auction house, gold sources and sinks, retention and revenue. Every server has its own economy, and your job is to keep it in the black.

The player-driven auction house and its trade-volume charts in MMOS
A real auction house: players list, bid and undercut each other, and deposit fees take gold back out of the economy.
MMO statistics in MMOS: subscribers, class distribution and daily concurrent users
Live stats track subscribers, class spread, dungeon clears and daily concurrent players, so you spot churn before it costs you.
FAQ

Questions about the MMO simulator

What is MMOS?
MMOS: MMO Simulator is a single-player management sim where you build and run your own fantasy MMORPG. You design the world and its content, and simulated adventurers log in and play it.
Is MMOS multiplayer?
No, it's single-player. Every adventurer on your server is simulated. They level up, group up, trade and form guilds on their own.
Is there a free demo?
Yes. The free demo is on Steam and itch.io. Download it from Steam or play it in your browser on itch.io, with no sign-up.
What platforms is MMOS on?
MMOS is on PC through Steam, where you can play the free demo and wishlist the full game. Versions for Google Play and the App Store are coming later.
What do you do in an MMO simulator game?
You build the world, then create the classes, loot, dungeons and raids. You run the economy and the servers, and your goal is to keep adventurers happy and subscribed.
How is it different from a tycoon or idle game?
You design the content and operate the game yourself. The adventurers act on their own, but every decision about their world is yours, and they react to each one.
Is MMOS an MMO tycoon game?
Yes. MMOS is an MMO tycoon and management game. You build the world, create its content and grow your subscriber count, and every player on your servers is a simulated adventurer.
Can I make my own MMORPG in MMOS?
Yes. You create races, classes, spells, items, monsters and dungeons in built-in editors, with no coding. Simulated adventurers then log in and play what you made.
I've played MMORPG Tycoon 2. What's different?
MMOS already has the endgame: factions, world PvP, arenas with ranked seasons, guilds that set their own goals, and raids for up to thirty adventurers. The economy is player driven, with professions, gathered materials and a live auction house where adventurers list, bid and undercut each other. The world has height, mounts and flying, a weekly calendar with events you fund, and you can click any adventurer to read what it plans to do next. The demo is free and runs in your browser.
When does MMOS come out?
MMOS: MMO Simulator launches on Steam on 11 December 2026. The free demo is out now on Steam and itch.io. Wishlist the game and Steam will tell you the day it goes live.
Is MMOS in Steam Next Fest?
Yes. The free MMOS demo is in Steam Next Fest from 19 October to 26 October. Download it on Steam, build your own MMO and see how long you keep its simulated adventurers subscribed.
Play now

Be there when the
servers go live.

Play the free demo today and wishlist MMOS on Steam before it launches on 11 December 2026. It's also coming to Google Play and the App Store, so you can run your MMO wherever you are.

Wishlist on SteamTry the free demo

Want to see what you can unlock? Explore the research tree.