Stellaris Dev Diary #293 – Introducing Coop


by Eladrin

Hello everyone!

One of the major Custodian features planned for the 3.8 ‘Gemini’ update is the addition of two cooperative gameplay modes. Up to five players will be able to control the same empire and work together to play the game as a team.

Two Modes of Play​

Surveys suggested that there are two distinctly different reasons people want to play together.

  • I want to play a PvE game of Stellaris with my friends, either to teach them how to play the game or to have a more relaxed game where we can share the duties of empire management.

Stellaris is a complex game, and learning to play can be difficult without a guiding hand. While some people learn well by watching informative videos created by the community, others might do better playing alongside a friend.

  • I want to play a multiplayer PvP game of Stellaris where teams of players go up against each other.

The cognitive load when playing competitive multiplayer can be at times overwhelming, especially during wars. Being able to split duties with other players on the same team could provide an enjoyable experience.

We’ve tried to support both goals through two different modes of play, with slightly different game rules.

Cooperative PvE​

A new main menu entry exists for starting a Cooperative PvE game where all human players control the same empire.

This will bring them to the Game Browser screen, where one of them can choose to Host a New Game, just like the regular Multiplayer flow.

The hosting player will go directly to Empire Selection, where they can create a new empire or select one they’ve already created as normal, select the Galaxy Settings for the game, and then begin the session.

Unlike regular Multiplayer, the Cooperative PvE flow bypasses the Game Lobby, and the coop players will not need to select an empire. These players hotjoin directly into the hosting player’s empire once the game has begun.

For most purposes, Cooperative PvE is treated the same way as single player PvE is.

Competitive PvP​

The flow for creating a competitive multiplayer coop game is similar to the normal multiplayer flow. One player will host the server, ticking the “Allow Coop” checkbox.

Other players can join the Game Lobby and open their empires up for additional players.


pdx_eladrin has opened his empire up for cooperative play.


After Loner has joined the empire.​

Empires that have been opened for cooperative play add an “inspect” icon to the portrait so prospective players can see the details on the empire before deciding to join.


Inspect a coop empire.​

For more competitive players, the primary player of the empire will be able to lock their empire, which will add a password requirement to joining or inspection.

New Coop Features​

It’s often useful to know what your teammates are up to. To make it a little easier to understand what’s going on, we’ve added Presence Markers to the UI to show which tabs your teammates are currently using.


pdx_eladrin is currently taking care of our research issues, so Loner can worry about something else.​

We’re currently exploring the addition of Goto buttons in the top right corner that will allow you to bring your camera to your teammate’s location, but this isn’t fully functional yet. (And is unlikely to be during the Open Beta.)

Events will be shown to all members of a coop team, and any of the players can select a response. The window will remain in place with the selected option marked with the icon of the player that made a choice.


Only one option for this one, but it’s nice to know it’s already been selected.​

What’s Next?​

Next week we’ll be talking about the 3.8 ‘Gemini’ Open Beta.

As the Coop game modes touch a lot of moving parts, we’d like to gain feedback on your thoughts of how it plays as well as find where desyncs and other bugs crop up before the actual release.

Written by: Burnsy - Community Leader