Multiplayer is included in the current Sector Rot demo as an early foundation for cooperative and online play.

At this stage, the system is functional enough for testing, but it should still be considered experimental. The main purpose of multiplayer in this demo is to collect feedback, identify connection problems and understand what needs to be improved before it becomes a fully stable feature.

What is currently available

Players can:

• create a local multiplayer server;
• host a game;
• join available sessions;
• use the current maps and gameplay systems in multiplayer;
• test cooperative gameplay with other players;
• use the local server component included with the game.

The Windows build already includes the required local server executable. Players do not need to install Python, a separate server package or additional development tools.

Important limitations

Because this is an Alpha demo, multiplayer may currently have issues such as:

• difficulty connecting to a host;
• sessions not appearing correctly in the server browser;
• firewall or antivirus prompts;
• ports being blocked by the router or Windows Firewall;
• players using different game versions;
• desynchronization between players;
• enemies, items or objectives behaving differently for connected players;
• save or progression data not synchronizing correctly;
• unexpected disconnects;
• unfinished interface messages;
• performance problems during larger encounters.

Some systems were originally developed for single-player and are still being adapted for multiplayer. This means that a feature working correctly alone may behave differently when several players are connected.

Recommended setup

For the best chance of a successful test:

1. Make sure every player uses the same Sector Rot version.
2. Make sure every player uses the same enabled gameplay mods.
3. Allow Sector Rot and SectorRot_Server.exe through Windows Firewall.
4. Start with an unmodified official map.
5. Test with two players before trying larger groups.
6. Avoid loading old saves created with another version.
7. Restart the game and server after changing mods.
8. Keep the complete game installation together and do not move individual executable files.

If Windows asks whether the game or server should be allowed through the firewall, select the appropriate private network option for trusted home or local networks.

Mods and multiplayer

Gameplay mods can affect multiplayer compatibility.

Every player should have:

• the same required mods;
• the same mod versions;
• the same load order;
• compatible map files;
• matching game data.

A missing or different weapon, enemy, class, map or configuration file can cause connection errors or inconsistent gameplay.

For the first tests, I recommend disabling all optional mods and using only the official demo content.

Hosting over the internet

Local network testing is expected to be easier than hosting across the internet.

Internet hosting may require:

• allowing the server through the firewall;
• router port forwarding;
• using the correct public IP address;
• checking whether the internet provider uses CGNAT;
• ensuring that the selected port is not already in use.

CGNAT or restricted router access may prevent direct hosting even when the game and firewall settings are correct.

A simpler connection system may be added in the future depending on testing results and community interest.

Before reporting a multiplayer problem

Please include:

• your Sector Rot version;
• the number of connected players;
• who was hosting;
• whether the test was LAN or internet-based;
• the selected map and mode;
• enabled mods;
• the exact error message;
• what happened before the problem appeared;
• whether Windows Firewall displayed a prompt;
• screenshots or logs, when available.

A useful report example:

Version 0.7.7, two players, internet connection, official tutorial map, no mods. The second player connected successfully but disconnected when the host entered the next map.

Reports like this make problems much easier to reproduce and fix.

Current goal

The multiplayer foundation is included now so it can be tested early instead of being hidden until much later in development.

Your feedback will help determine:

• which connection problems are most common;
• whether cooperative play is enjoyable;
• which systems fail to synchronize;
• what interface improvements are needed;
• whether multiplayer should become a major part of Sector Rot.

Please expect bugs and unfinished behavior during this stage. Multiplayer will continue to improve based on real testing and community reports.

For help, testing groups or bug reports, contact me through Discord or leave a message in the Sector Rot community section.

Thank you for testing Sector Rot.