Schedule 1 Multiplayer With More Than 4 Players: Mods vs Dedicated Server

Schedule I supports co-op for up to 4 players, and that is the limit the game ships with. If your group is five or more, there are two ways past it: a community mod that raises the lobby size, or a dedicated server running the S1DedicatedServers mod. They solve different problems, so this guide explains how each works, what every player has to install, and which one fits your group.

How many players can play Schedule 1?

Out of the box, 4 players. TVGS announced co-op in January 2025 and it shipped with the early access launch on 24 March 2025. It works as host based co-op: one player hosts the game from their own PC and up to three friends join through Steam.

That design has two limits that matter for bigger groups:

• The cap is 4. There is no setting in the game to raise it.
• The world only runs while the host plays. When the host quits, the session ends for everyone, and nobody can grow product or run deals while the host is offline.

There is no official dedicated server. Everything past 4 players comes from community mods, which TVGS does not make or support. Results vary between game versions, so read each mod's page for its current status before you rely on it.

Option 1: Lobby size mods

Lobby mods keep normal co-op exactly as it is, but raise the player cap. Two are well known on the Schedule I Thunderstore community:

ifBars, the author of BiggerLobbies, also makes S1DedicatedServers, the dedicated server mod covered below.

What each player installs

• Everyone in the lobby needs the same lobby mod, on the same version, installed with its mod loader as described on the mod's Thunderstore page.
• Everyone needs the same game version. After a Schedule I update, a lobby mod can stop working until its author updates it.

What stays the same

A lobby mod does not change how co-op works underneath. It is still host based:

• The host's PC runs the whole world, the NPCs, every player's actions and all the network traffic. Each extra player adds load to that one machine and its upload connection.
• When the host leaves, the world closes for everyone.
• The save lives on the host's PC, so only the host can continue that world.

Pros and cons

Pros: free, quick to set up, uses the normal Steam invite flow, and no extra machine is needed.

Cons: the host's PC and home connection become the bottleneck, performance drops as the lobby fills, nobody can play without the host, and every player has to keep the mod in sync.

Option 2: A dedicated server with S1DS

S1DedicatedServers (S1DS) is a free, open source mod that runs a full copy of Schedule I with no graphics as a dedicated server. Nobody plays on the server itself: everyone, including the owner, connects to it as a normal player.

S1DS does not use the vanilla 4 player lobby cap for direct IP joins. The server owner decides the limit.

What each player installs

• MelonLoader (versions 0.6.x, 0.7.0 or 0.7.2 and newer, not 0.7.1).
• The S1DS client package for the server's runtime: Il2cpp_Client.zip for the normal Steam version, or Mono-Client.zip for the alternate beta branch.
• The same game version as the server.

The step by step install is in how to join a Schedule 1 dedicated server. The client mod can stay installed for single player and normal co-op, because its dedicated server features only switch on when you join an S1DS server.

What changes

• The world is always on. Friends in different time zones can play whenever they like. The owner can also set pauseGameWhenEmpty = true if the world should stop while nobody is online.
• Nobody is the host. The owner is just another player, so their PC only renders their own game.
• Real admin tools. Staff can kick, ban, teleport players and save on demand. See Schedule 1 dedicated server commands.
• Someone has to run the server. Either a PC that stays on, with ports forwarded, or a rented server.

Pros and cons

Pros: higher player limits, a world that never closes when one person logs off, no single player carrying the load, proper moderation, and automatic saves every 15 minutes by default.

Cons: more setup. The server needs its own copy of the game from an account that owns it, a machine with spare CPU and RAM, and updating whenever the game or mod changes. Everyone must match the server's game version and runtime.

Side by side

For a general look at host based play versus servers in any game, see dedicated server vs peer to peer.

Performance notes

Schedule I is not a light game. The official minimum spec asks for 8 GB of RAM just to play.

With a lobby mod, the host's computer does its normal job of running the game for its own player, and on top of that simulates the world for everyone else. With 8 or more players, expect lower frame rates for the host and more rubber banding for everyone, especially on a home upload connection. How far you can push it depends on the host's hardware and connection, so try your group size before committing to a long save.

With a dedicated server, the load moves to a machine that does nothing else. The S1DS docs list 2 vCPUs at about 2.0 GHz and 4 GB of RAM as the bare minimum, and that setup ran at about 72% CPU and 3.0 GB of RAM with only 0 to 1 players. More players, bigger operations and more employees all need more headroom. As a rough guide:

Larger groups toward the 64 cap need a strong CPU as well as more memory. More detail in how much RAM a game server needs.

Which should you pick?

Pick a lobby mod if:

• Your group always plays together, at the same time.
• One person has a strong PC and a good upload connection and is happy to host.
• You want to try a bigger lobby tonight without renting or setting up anything.

Pick a dedicated server if:

• Friends want to play at different times, or the host is often busy.
• You have more than a handful of players, or want to go past 20.
• You want to kick, ban or manage staff.
• You want an existing world to carry on. Moving a co-op save across is covered in how to transfer a Schedule 1 save to a dedicated server.

Both routes need every player to install mods, so the mod install is not the deciding factor. The real question is whether your world should close when the host goes to bed.

Setting up a dedicated server

To run S1DS yourself, follow how to make a Schedule 1 dedicated server. It covers Windows, Linux with Wine or Docker, the config file and the ports you need to forward (see also how to port forward a game server).

If you would rather skip that part, a hosted Schedule I server comes with the game, MelonLoader and S1DS installed and configured, and needs no port forwarding. Plans run from 6 GB for up to 4 players at 14.99 USD a month to 12 GB for up to 16 players at 29.99, and you can split the bill with up to 10 friends. Each server has an invite page that walks your players through the client mod install. The quick start shows the full setup.

FAQ

How many players can play Schedule 1 multiplayer?

Up to 4 in the base game. Lobby mods raise that to around 20, and an S1DS dedicated server allows 16 by default and up to 64.

Is there an official way to play Schedule 1 with more than 4 players?

No. Every option beyond 4 players is a community mod.

Do all players need the mod to join a bigger lobby?

Yes. With MultiplayerPlus or BiggerLobbies, everyone in the lobby needs the same mod and version. With a dedicated server, everyone needs MelonLoader and the S1DS client.

Does a lobby mod keep the world online when the host leaves?

No. Lobby mods only raise the player cap. The world still runs on the host's PC and closes when they quit.

Can I use a lobby mod and S1DS together?

They solve the same problem in different ways, so you do not need both. On an S1DS server the player limit comes from maxPlayers in the server config, not from a lobby mod.

Will more players make Schedule 1 lag?

With a lobby mod, every extra player adds load to the host's PC and connection, so yes, usually. On a dedicated server the load sits on the server, so give it enough CPU and RAM for your group size.