How to Play Icarus With Friends

Short answer: you can either host from your own game client and invite Steam friends, or join a dedicated server. The difference that matters is not player count — it is that a peer-to-peer world only exists while its original host is online, and nobody else can ever resume it.

Icarus is PvE only, so this is entirely about co-op. Here is how each option actually behaves.

Checked against Icarus 3.0.27.157242-rel-DangerousHorizons

Week 249, released 10 September 2026. The server browser came out of beta in Week 244, 6 August 2026.

The two ways to play together

RocketWerkz recommend the second for persistent play. The Icarus Steam page: "invite up to 8 Steam friends to join your game or play on dedicated servers. Dedicated servers are free to run and are recommended for Open World sessions."

The rule that decides it for most groups

When Icarus moved all player data onto players' own machines in Week 53, peer-to-peer hosting picked up a hard constraint:

"That original host must always be online. From now on the player who initially created the mission will be the only one able to resume it. Other players will not be able to carry on or launch a mission that another player has started, as this save data is now stored on the initial host's hard drive rather than in the cloud."

Host migration used to paper over this. It no longer exists — RocketWerkz confirmed in the same post that the feature "won't exist in the new data decentralized model".

So on a peer-to-peer world, one person's schedule is everybody's schedule. If they are away for a fortnight, the base is away for a fortnight. That is the single most common reason groups move to a hosted Icarus server, and it has nothing to do with performance.

On peer-to-peer, the host leaves last

RocketWerkz's guidance is blunt: "the host should always be the last person to leave a prospect. This way, players are guaranteed to be able to recover their gear and claim any rewards." If the host drops out first, everyone still on the planet is disconnected mid-session.

How many players, really

Two different limits get muddled together, and RocketWerkz named them separately:

• Prospect Limit — the total number of players who have ever joined a world. This used to be 8 and was removed entirely in Week 54. As many people as you like can pass through a world over its lifetime.
• Session Limit — how many are active at once. Peer-to-peer is capped at 8.

For dedicated servers, RocketWerkz wrote in that same update that they "will be opened up to more than 8 players, but at the risk of server degradation as this session count fluctuates". Their configuration reference, however, still documents MaxPlayers as "Minimum 1, Maximum 8", and the store page still describes eight-player co-op. Plan for 8. Anything beyond it is untested rather than supported.

Joining a dedicated server

From RocketWerkz's own instructions:

1. Launch Icarus and select your character.
2. Choose Join Session from the HAB menu.
3. Use the toggle in the top-right of the screen to switch the browser from peer-to-peer sessions to dedicated servers.
4. Select your server and join.

If the server has no prospect running, you do not get an error — you land in the Server Lobby. That screen lets an admin run commands and pick which prospect or Outpost the server should load. It is the normal state for an empty server, not a fault.

Any character you own can be taken into any session, so there is nothing to create or transfer first. What that means for progression is covered in Does Icarus Progress Save on a Dedicated Server?.

If the server is not in the list

Since the Week 244 browser update, the Matching Version filter is on by default. RocketWerkz: "By default, only sessions/servers with a version matching the client are displayed." A server that has not taken this week's patch is invisible to almost everybody, and it looks identical to a server that is down.

Work through it in this order:

1. Version. Is the server on the current build? This is the cause far more often than anything else.
2. The filter itself. It can be turned off in the browser if you genuinely need to see mismatched servers.
3. The toggle. Make sure the browser is showing dedicated servers, not peer-to-peer sessions.
4. Query port. Steam server-list features run over the query port; if it is wrong or blocked, the server never advertises.

Week 244 also fixed two long-standing annoyances worth knowing about: filters no longer leak non-matching servers into the list while a search is running, and friends in the same peer-to-peer session no longer appear as duplicate entries.

Keeping a server private

Set JoinPassword in ServerSettings.ini and share it with your group. RocketWerkz describe it simply as the "Password required to join the server" — leaving it empty means no password at all.

Set AdminPassword at the same time. Left empty, RocketWerkz warn that "just using the RCON /AdminLogin will give admin privilege's to a player" — meaning any joiner can kick, ban or dump the session back to the lobby. Both are covered in Icarus Server Settings Explained.

For moderating people once they are in, the command set is short and chat-based — no RCON tool will connect. Icarus Console Commands: What Actually Works has all seven of them.

Common Questions

Is Icarus PvP?

No. Icarus is a PvE survival game. There is no PvP mode, so co-op servers are cooperative by design rather than by configuration.

Can my friends play on my world when I am offline?

Only on a dedicated server. On a peer-to-peer world, the original host must be online — nobody else can resume it.

Can more than 8 players join an Icarus server?

More than 8 can join a world over its lifetime; the supported concurrent figure is 8. RocketWerkz document MaxPlayers at a maximum of 8, and the store page still describes eight-player co-op.

Do we all need the DLC maps?

To play on a DLC map, yes — Elysium, for example, ships with the Dangerous Horizons expansion. Base-game maps and the free Arcwood Outpost need nothing extra.

My friend's server does not show up — why?

Most likely a version mismatch. The browser filters to matching versions by default, so an out-of-date server is hidden rather than shown as offline.

Does everyone need to be at the same level?

No. Characters are independent and any character can join any session. Expect a wide power gap if you mix a level 60 with a new prospector — there is no server setting that levels that out.

What to Read Next

• Icarus Console Commands: What Actually Works — kicking, banning and admin login
• How to Set Up an Icarus Dedicated Server — install, ports and first boot
• Icarus Prospects on a Dedicated Server — why an empty server returns to the lobby
• Does Icarus Progress Save on a Dedicated Server? — what your character keeps

---

Made with 💜 by GameServerKings