Quick Answer
MachineParty+ (MP+) is a community-built mod that adds the multiplayer features the official game is missing. It's an expansion on top of the community mod loader — you need to install the loader first, then drop MP+ into the mods folder.
What it adds, in plain terms:
- A global server browser (replaces the JOIN button on the main menu).
- Public lobbies you can browse and join from anywhere — not gated to your friends list.
- In-game text and voice chat (the official game has neither).
- Kick and ban controls.
- A scoreboard (hold Tab).
- Room naming and player-cap controls.
A few things that catch first-time users off guard — and this is what this page is mostly about:
- It works in three different ways with three different groups of players. That layering trips people up.
- It still requires the same community loader with the same risks as the loader itself.
- As of August 13, 2026, there's no public "yes it works after v2.0" statement from the project. The README references the v2.0 couch co-op feature, but a definitive compatibility line hasn't been published.
What It Actually Adds
Based on the project's own documentation, MP+ adds the following to the base game:
| Feature | What it does |
|---|---|
| Server browser | A global lobby list that replaces the default JOIN button. Browses rooms from other modded players anywhere |
| Public lobby toggle | "Make Lobby Public" flag inside a room — controls whether your room shows up in the global browser. Default is still private, so don't expect every modded room to be visible |
| Room naming | Custom room names that show up in the browser, so you can label your group |
| Max player cap | Adjustable room cap |
| Text chat | In-game text chat (the official game has no chat at all) |
| Voice chat | In-game voice chat (the official game has no voice either) |
| Kick and ban | Host controls to remove disruptive players from your lobby |
| Scoreboard | Hold Tab to see scores during the match |
Everything here is modded-only — players who don't have the mod installed won't see any of it.
Compatibility: The Three-Layer Answer
This is the question people ask first, and the answer is layered. All three layers matter:
Layer 1 — Private lobbies still work across modded and vanilla players
If you have MP+ installed and you start a private room, you can still give your 18-digit room code to a friend who has no mods installed and they will be able to join you and play the match. The match itself runs; the gameplay is unchanged. This is the most important compatibility point and it's the one most people care about.
Layer 2 — Public lobby browser is modded-only
The server browser, public lobby toggle, and room naming all rely on the mod being installed on both ends. If your friend has no mod, they will not see your public room in their browser. They can still join via room code (Layer 1).
Layer 3 — Voice and text chat are modded-only
In-game text and voice chat only function between modded players. If you have MP+ and your friend doesn't, you can still play with them via room code — but you can't talk to them through the game's chat. (Most groups fall back to Discord or Steam Voice for cross-installation voice anyway.)
So the practical summary is: MP+ doesn't lock you out of playing with vanilla friends, but the modded-only features only work between modded players. If everyone in your group installs MP+, you get everything. If only some of you install it, you get the gameplay but lose the chat and the browser for the cross-installation sessions.
Known Limits
A few things the project documentation calls out:
- Steam's in-game Invite button stops working once MP+ is installed. This is a side effect of the mod loader's overlay on top of Steam's interface. After installing MP+, you have to share the 18-digit room code directly with your friends — the Steam Invite button will not work.
- Game updates can break the loader, which breaks MP+. MP+'s own README says: "a future Machine Party update can temporarily break the loader (and with it, this mod). If that happens, don't panic and don't keep reinstalling. Wait until the mod loader pushes an update that fixes it, then update the loader and launch again."
- MP+ is online-focused. The project's README has a section titled "Local couch co-op (Machine Party v2)" noting that MP+ is designed for online play and "stays out of local play" — i.e., if you're playing couch co-op, MP+ features are not active.
- There is no public v2.0 compatibility statement. The project's documentation references the v2.0 couch co-op feature in the context of explaining why MP+ doesn't apply to local play, but it does not say "tested and works after v2.0." Treat the post-v2.0 status as "unconfirmed" until the project publishes otherwise.
Why the Mod Exists in the First Place
The developers have explicitly said they will not add public matchmaking or public lobbies to the official game. From the v1.5 announcement: the original design vision is for friend groups rather than random matchmaking, so a public lobby system is not in scope. The official substitute is the Discord LFG channel.
MP+ is the community's response to that gap. If you don't have a regular group, and the Discord LFG doesn't turn up a match, MP+ gives you the public-lobby and chat tools the official game refuses to ship.
Same Caveats as Any Mod
The four risks listed on the mods overview page — .pck rewriting, update fragility, unaudited AI-assisted code, and unstated developer policy — all apply to MP+. Read that page before you decide to install anything.
For a deeper look at how the mod ecosystem works in general, see the mods overview.