Configure the server and world
A Core Keeper server has only a handful of settings: world name, seed, mode and maximum number of players. They are set from the Startup tab of the Game Panel. This page covers each of them, along with Game ID management.
Changing settings safely
Always stop the server from the panel Console before changing a setting. Settings are only read at startup: a change made while the server is running only takes effect on the next launch.
- Log in to your Game Panel: game.yorkhost.fr
- Select your server and stop it
- Open the Startup tab
- Change the variables you need (exact labels may vary slightly depending on the panel version)
- Start the server and check the Console
Before touching the world (seed, mode, world slot), create a backup from the Backups tab. See Import a world and backups.
World settings
Core Keeper's official dedicated server is configured through launch parameters. The Startup tab presents them as variables; the table below shows which official parameter each one maps to, for reference.
| Setting | Official parameter | Purpose |
|---|---|---|
| World name | -worldname | Name of the world / game |
| Seed | -worldseed | Seed used to generate a new world. 0 = random seed |
| World mode | -worldmode | Standard, Hard, Creative or Casual (see below) |
| Max players | -maxplayers | Maximum number of players connected at the same time |
| World slot | -world | Number of the world to load (0 by default), if this setting is exposed in your Startup tab |
Depending on the version, the server also stores its settings in a ServerConfig.json file, in its data folder (see Where are worlds stored?). The Startup tab variables remain the reference: if a change to that file seems to be ignored, the same value is probably set in Startup.
World name
The name identifies your world. You can change it at any time while the server is stopped.
Seed
The seed drives world generation: two worlds created with the same seed share the same layout. Leave 0 for a random seed, or enter a specific seed (shared by a friend or found online).
Changing the seed of a world that already exists doesn't regenerate it. To play on another seed, you need to create a new world: see Start a new world.
World mode
| Mode | Usual value | Best for |
|---|---|---|
| Standard (Normal) | 0 | The adventure as the developers intended: exploration, bosses, farming, building |
| Hard | 1 | Tougher enemies and mistakes that cost more, for seasoned groups |
| Creative | 2 | Free access to items to build without resource limits |
| Casual | 4 | A more relaxed, less punishing experience |
The numeric values come from the official dedicated server documentation and may change with game versions: if the Startup tab offers a list or a description, go with that.
The mode is set when the world is created. Changing it on an existing world usually doesn't have the expected effect. To switch modes, the safest option is to generate a new world and keep the old one as a backup: see Start a new world.
Player count
Core Keeper officially supports 8 simultaneous players. The MaxPlayers setting lets you raise that cap, but the developer doesn't guarantee the experience beyond 8 players.
- For a small group, you can lower the cap to avoid unexpected connections.
- If you go past 8 players, keep some RAM headroom: an Octarine or Galaxite plan is recommended (see Getting started).
Game ID and access control
The Game ID is the identifier players enter to join your server (see Getting the Game ID). It works as an access key:
- Only share it with the players you invite
- Avoid posting it on a public Discord server or showing it on stream
- Check it after every restart: depending on the configuration, it may stay the same or be regenerated at startup. If your friends can no longer find the game, copy the Game ID shown in the console again
The official dedicated server accepts a -gameid parameter to force a specific identifier. If it isn't exposed in your Startup tab and your Game ID has been shared too widely, contact support.
As far as we know, the Core Keeper dedicated server doesn't provide an admin list or moderation commands (kick, ban) comparable to other games. Access control relies on keeping the Game ID private and on the maximum number of players. If in doubt about your version, contact support.
Ports
The IP:PORT address shown in the panel is assigned to your server. With the Game ID connection, players don't need it. Don't change ports manually in the server files: port opening is handled by YorkHost (see Are all ports open?).