How to Make a Private SCP: Secret Laboratory Server
SCP:SL is free, chaotic, and at its best with exactly the people you chose - which is why "how do I make a private server" is the most asked hosting question in the community. The good news: private is not a special server type. It is a normal dedicated server with two switches set.
The two switches
- Unlisted visibility. Keep the server off the public list and it is invisible to strangers. Your group joins by IP and port, which you drop once in your Discord. Nobody who does not have the address will ever see the server exists.
- Whitelist (optional, stricter). If a shared link is not enough control - links travel - enable the whitelist so only approved players get in even with the address.
That is the entire concept. And because both are just settings, the day your group wants an audience, the same server with the same configs and plugins flips to public and listed.
What running the server actually involves
The dedicated server software is free and installs via SteamCMD with anonymous login - the game being free-to-play does not change anything server-side. A self-hosted setup means:
- a machine that stays on when your group plays, with a fast CPU core - SCP:SL rounds are single-thread heavy, and clock speed decides whether a full 20-30 player round feels crisp;
- port forwarding on your router so friends outside your network can reach it;
- keeping the server updated - the game patches often, and client and server must match or joins fail;
- config maintenance: round rules, friendly fire, respawn behaviour, and later the plugin stack.
A managed SCP:SL server is the same thing with the machine, ports, updates and backups handled - you keep the two switches, the configs and the staff roles.
The parts every private facility ends up wanting
Plugins. Almost every serious SCP:SL server runs them, and the de-facto framework is EXILED - custom classes, round events, moderation helpers. Plugins install server-side; your players need nothing. The maintenance reality is that game updates can break plugins, so update on your schedule with a backup first, not automatically mid-week.
Remote Admin roles. SCP:SL has a built-in Remote Admin system with per-role permissions. Give your moderators exactly the powers you want them to have - kicks, bans, round tools - from inside the game, without anyone touching the server itself.
Round rules that fit your group. Friendly fire on or off is the personality question; round-restart timing and respawn behaviour decide the pace of an evening. These live in the server config and apply on the next round.
Common join problems on private servers
- Version mismatch - the game updated and one side did not. Restart Steam, update the server.
- "I can't find it in the browser" - correct, it is unlisted. Join by IP and port.
- One player rejected, everyone else fine - check the whitelist before anything else.
- Nobody can join for a moment - the server refuses joins during a round restart; wait it out.