The short version: there is no free, offline, split-screen city builder on Windows 10 that lets two people build on one screen at the same time, so stop searching for that unicorn. What you can get, for free, is hotseat play (you take turns on the same city) or two instances running on one machine over a local network connection, and I'll show you exactly how to set both up.
Why this search is harder than it looks
I went looking for this because my nephew asked me to help him find a city builder he and his mate could play together on one old Windows 10 laptop, no internet, no card details, nothing. Every "best free two player city building games" list I found online was recycling the same ten titles, half of which are mobile games, and none of which support two people on one PC at the same time.
Here's the uncomfortable bit most round-ups won't say out loud: real simultaneous co-op city building, where you and a mate are both placing roads and zoning housing at the same moment on the same save, barely exists even in paid games. Cities: Skylines doesn't do it. SimCity never did it. The genre is built around one person managing one city, so "two player" almost always means one of three things: hotseat (alternating turns on one save), split network play (two copies of the game talking to each other over LAN, even on one PC), or asymmetric multiplayer where one person builds and the other does something else entirely, like trading or diplomacy.
Once you accept that, the search gets much easier because you stop chasing something that was never built.
The games that work, free and offline
These are real PC titles, not mobile ports dressed up in a desktop wrapper, and all of them run fine on a modest Windows 10 machine with 4GB of RAM.
- OpenTTD - free, open source, this is a transport and city-growth sim built from the old Transport Tycoon code. It supports multiplayer natively, including hosting a server on your own PC and joining it with a second client window, so two people on one machine can manage the same map.
- Unknown Horizons - free, open source, an Anno-style settlement and trade game. It has a built-in multiplayer lobby and runs two client windows happily on one laptop if you've got 4GB of RAM free, which most Windows 10 machines bought in the last six years will manage.
- Widelands - free, open source, a settlement builder closer to Settlers than SimCity, with a genuine LAN multiplayer mode that works over loopback (more on that below).
- Simutrans - free, open source, transport and economy focused rather than pure city-building, but it has a server mode that two players can join from the same PC.
- 0 A.D. - technically a real-time strategy game rather than a pure city builder, but the base-building and resource management is close enough that it scratches the same itch, and it has solid LAN support.
None of these need a license key, an account, or a connection once they're installed. That's the actual "offline" promise most app store listings quietly ignore.
Worked example: setting up two players on one PC
Say you've downloaded Unknown Horizons on a Windows 10 laptop with 4GB of RAM and a mid-range processor from the last five years. Here's the step-by-step to get two players going on that single machine:
- Install the game once (around 300MB download, so check your connection or do it on wifi before you go offline).
- Launch the game, go into multiplayer, and host a new game. This spins up a local server on your machine using the address 127.0.0.1, which is your own PC talking to itself.
- Minimise that window, launch a second instance of the game (right-click the shortcut and open it again, or run the executable twice from the install folder).
- In the second window, join multiplayer and connect to 127.0.0.1. It'll find the first instance instantly because it never left the machine.
- Pick your settlements, hit start, and you're both building on the same map from one laptop with zero internet involved after the initial install.
Performance note: running two instances at once roughly doubles the RAM load, so on a bottom-end 4GB machine expect some lag if you've also got Chrome open with eleven tabs. Close the browser first.
If you can't get loopback working
Hotseat is the fallback and it's not a bad one. OpenTTD and most of the open source titles above support saving mid-game and handing the keyboard over, so one person plays a turn (building, zoning, expanding) then passes control to the other. It's slower but it needs no network setup at all, which matters if you're on a work laptop with group policy locking down localhost connections, which happens more often than people admit.
If the two players are on separate machines rather than one shared PC, all five games above support real LAN play over a home network, same install, same steps, just two different computers instead of two windows on one.
What to skip entirely
Avoid anything from the Microsoft Store promising "free city builder, multiplayer" with a four-star rating and a few thousand downloads. I checked a stack of these while sorting this list out and most are either ad-funded shells wrapping a single-player loop with a fake multiplayer tab, or they want an account and an internet connection the moment you open them, which breaks the entire "offline" requirement. If an app needs sign-in before you've placed a single building, it's not offline, whatever the listing claims.
Want AI doing the heavy lifting in your marketing?
I build the systems that handle the boring 80 percent, so you get your week back. Done properly, with the human kept in.
Also skip anything billed as "two player split screen" for PC city builders. I haven't found one that exists in this genre, free or paid, and I'd rather tell you that plainly than send you downloading three different 500MB installers hunting for a feature that isn't there.
Related free offline gaming if this isn't quite it
If the Windows 10 laptop is for the kids and you want something lighter and more mobile, our breakdown of free offline city building games for iPhone under 50MB covers titles that install in seconds and don't eat storage. If it's a Chromebook in the house rather than a real Windows machine, the free offline farming games for Chromebook with two players list solves a near-identical problem for a different genre, with the same loopback and hotseat logic applying.
For anyone whose actual interest is management and strategy rather than specifically city layouts, our free offline simulation games for Chromebook without wifi piece widens the net a bit, and if the appeal is really about building worlds rather than cities specifically, the free offline open world games for 4GB RAM under 50MB list has lighter options that run on old hardware.
None of that is padding for the sake of it, it's the honest map of where this search tends to lead once people realise the exact phrase they typed doesn't have a clean answer.
Frequently asked questions
Is there a truly free city building game with split screen on PC?
No, not in this genre. Split screen city builders for PC don't exist as free titles or paid ones as far as I could find. What does exist, free, is hotseat play and two-instance LAN play on one machine, both covered above.
Can two people play OpenTTD on one laptop without internet?
Yes. Host a server from the game's multiplayer menu using your own machine's loopback address, 127.0.0.1, open a second instance of the game, and join that address from the second window. No internet connection is required once OpenTTD is installed.
Why do app store listings claim two player and then ask for an account?
Because "multiplayer" on mobile and Microsoft Store listings almost always means online matchmaking against strangers or friends over the internet, not local two player on one device. If an app needs sign-in before gameplay starts, it isn't offline, regardless of what the store description says.
Will these games run on a 4GB RAM Windows 10 laptop?
Yes, OpenTTD, Unknown Horizons, Widelands and Simutrans are all light by modern standards and were built to run on much older hardware than a typical 2026 Windows 10 machine. Running two instances at once for loopback multiplayer roughly doubles the RAM use, so close other heavy programs first.
