Six people, one room, one router, and no reason for any of the traffic to leave the building. Or one person on a train wanting to test a server configuration with no connection at all.
Both of these still work in a lot of games and quietly stopped working in others, and the difference is not always obvious until the evening you have planned around it.
Two different things
LAN play means several machines on the same local network, talking to each other directly. The internet may or may not be present.
Offline play means no internet connection at all, which is a stricter requirement, because a surprising amount of software checks in with something remote before it will let you do anything.
A game can support LAN perfectly and still refuse to start without an internet connection, and that is the case that catches people out.
What still works
Source-engine games. Counter-Strike, Team Fortress, Half-Life, Day of Defeat, Garry's Mod and their relatives all run a dedicated server locally and all have a LAN tab in the browser. This is the most reliably LAN-friendly family of games there is, and the older ones in particular were designed in an era when LAN was the normal case.
Minecraft Java. Open to LAN from a single-player world, or run a dedicated server on the network. Works offline if the server is set to not verify accounts, which has a real security implication covered below.
Most survival and building games with a dedicated server binary. Valheim, Terraria, Factorio, Project Zomboid and many others run a server you can point at a local address.
Anything with a listen server. Where one player hosts from inside their own game, dedicated versus listen server covers the difference and why the dedicated version is better once you have more than a handful of people.
The things that do not
Anything requiring an always-on account check. Many modern titles verify entitlement with a remote service before letting you connect anywhere, including to a machine two metres away.
FiveM. Requires the client to authenticate and the server to be registered. Not an offline-capable platform.
Games where matchmaking is the only path. If there is no server browser and no direct connect, there is usually no LAN.
Minecraft Bedrock, partially. Local network discovery works between devices, but some platforms tie it to an account state that needs connectivity. Bedrock or Java covers the edition differences.
The way to check without hoping: look for whether the game ships a dedicated server binary you can run yourself. If it does, LAN almost certainly works. If everything goes through a launcher and a matchmaker, it almost certainly does not.
Setting up a LAN game
Find the host machine's local address. ipconfig on Windows, ip addr on Linux. It will start with 192.168, 10., or 172.16–31.
Start the server on it. A dedicated server binary if the game has one, or open-to-LAN from inside the game.
Everyone else connects to that address, with the port. The LAN tab in a Source browser will usually find it automatically; otherwise use direct connect. Connecting by IP covers the mechanics per game.
Open the firewall on the host. The single most common failure. Windows in particular blocks incoming connections on a network it has classified as public, and a router restart or a new cable can silently reclassify a network. If nobody can see the server, check this before anything else.
Do not port-forward. For a purely local game, nothing needs to reach the router from outside. Port forwarding is for the opposite case.
The dedicated-server-on-a-laptop trick
For an event, the arrangement that works best is a dedicated server on a machine that is not playing.
Why it is better than one person hosting from inside their game: the host's performance stops affecting everyone else, the host can leave without ending the session, and the server survives one machine crashing. A laptop nobody is using is enough for most games at LAN sizes.
A cheap laptop handles more than people expect at eight or twelve players, because LAN removes the bandwidth constraint entirely — the limitation is CPU, and eight players is not much CPU. Hardware specs covers the general question.
Wired, if you can. Wireless works and adds latency and jitter that is noticeable in shooters. For a room of people who came specifically to play, a switch and some cables are worth the twenty minutes.
The offline-mode security note
Worth stating plainly because it is easy to enable and easy to forget.
Several games have an option to skip account verification; online-mode=false in Minecraft, and equivalents elsewhere. This is what makes offline play possible, and it also means the server has no way to verify that anyone is who they claim to be.
On a local network with people in the room, this is fine.
On a server reachable from the internet, it is not. Anyone can connect as anyone, including as an administrator. This is a well-known and heavily-scanned misconfiguration, and it is one of the more common ways a small server is taken over. Game server security basics covers the wider picture.
If you enable it for a LAN party, turn it off afterwards, or firewall the server so it is only reachable locally.
Running a LAN event
Test the day before. Every failure at a LAN party is a firewall, a version mismatch or a missing content download, and all three are twenty minutes of preparation.
Pin the version. Everyone on the same build. Auto-updating launchers are the classic way a room of eight people ends up unable to play together.
Pre-download custom content. If the server has maps or mods, get them onto every machine beforehand, over a local network, ideally. Why modded servers take so long to join applies, and doing it eight times simultaneously over one internet connection is not a good use of an evening.
Have a second game ready. Something with no dependencies at all, for when the first thing does not work.
Write down the server address and put it somewhere visible. It saves being asked eight times.
Playing offline for other reasons
Testing a server configuration. Running the server on your own machine and connecting to 127.0.0.1 is the correct way to test a config change before it reaches anyone. Updating without breaking things is largely an argument for having somewhere to test.
Learning a map. Many games let you load a map locally with bots or alone, which is how people learn surf and KZ routes without occupying a slot on a public server.
Playing with bots. Older shooters in particular have good bot support, and a local server with bots is a legitimate way to play a game whose servers are empty at your hour.
Bots, where a room is short of people
Frequently the difference between a LAN evening working and not, and it is worth checking in advance which of your games support them.
Older shooters have excellent bot support. Counter-Strike 1.6, Counter-Strike: Source, the Unreal Tournament line and the Quake family all ship or support bots good enough to fill a server. Six people plus ten bots is a considerably better game than six people on a map built for thirty-two.
Bot counts are configurable per team, which is how you balance an odd number of humans without anyone sitting out.
Difficulty is worth tuning downward. Default bot difficulty in several of these games is unpleasantly high, and a room of people who mostly do not play shooters will have a better evening against easier opponents.
Some games count bots in the player count, which matters not at all on a LAN and matters on a public server: what a player count really tells you covers that side.
Survival and building games generally have none, and do not need them.
The practical advice for an event: test the bot configuration the day before with two people. Working out the console commands while eight people wait is a poor use of the evening.
The failures that ruin a LAN evening
In the order they occur, from twenty years of the same room and the same problems.
The host's firewall. Windows silently blocks incoming connections on a network it has classified as public, and a new router, a new cable or a fresh install reclassifies it. If nobody can see the server, this is the answer more often than everything else combined.
Version mismatch. One person's launcher updated on the way over. Pin versions in advance, or accept that somebody will spend the first twenty minutes downloading a rollback.
Missing content. Custom maps or mods that everyone needs and only the host has. Copy them onto a memory stick beforehand; downloading them eight times over one connection is not an evening.
Wireless. It works and it is worse. Jitter on a shared access point with eight machines is noticeable in anything competitive, and it produces complaints that get blamed on the server.
Nobody wrote the address down. Trivial and it costs ten minutes of asking.
The host has to leave. If one person is hosting from inside their game, the session ends when they do. This is the whole argument for a dedicated server on a machine nobody is playing on — dedicated versus listen server covers the difference.
All six are solved the day before, in about half an hour. None of them are solved on the night.
To sum up
Older games and anything with a dedicated server binary: LAN works, offline usually works, and it is the environment those games were built for.
Modern account-gated titles: usually not, and no configuration fixes it.
Check for a dedicated server binary, open the host's firewall, use wired connections if you have them, and test the day before. That covers nearly every LAN evening that goes wrong.
Published · 7 min read