Running a server

A dedicated server runs on Source SDK Base 2013 Dedicated Server from SteamCMD (app 244310), with Hidden: Rebuild's server package and Hidden: Source Beta 4b next to it. SteamCMD's server has the 64-bit engine but only 32-bit launchers, which can't load the mod; the server package brings the 64-bit launcher.

Install the dedicated server:

steamcmd +force_install_dir /path/to/server +login anonymous +app_update 244310 validate +quit

Download the server package for your system from the releases (hidden2013-<version>-windows-server.zip or -linux-server.tar.gz) and extract it into the server's folder.
Put Beta 4b's hidden folder there too (hsb4b-full.zip has it). The server's folder then has:

bin/ hl2/ hl2mp/ platform/ from SteamCMD hidden/ Hidden: Source Beta 4b hidden2013/ Hidden: Rebuild srcds_win64.exe or srcds_linux64 Hidden: Rebuild's 64-bit launcher

Windows

srcds_win64.exe -console -game hidden2013 +maxplayers 12 +map hdn_docks

Linux

Two one-time steps. Beta 4b has file and folder names with capitals (materials/Wall, ...), and the engine looks everything up in lower case, which Linux's case-sensitive file system doesn't find. The server package brings a script that lower-cases the names in the hidden folder:

sh hidden2013/lowercase_beta4b.sh

And the Steamworks library looks for the 64-bit steamclient.so in ~/.steam/sdk64. SteamCMD has it; link it there:

mkdir -p ~/.steam/sdk64
ln -s /path/to/steamcmd/linux64/steamclient.so ~/.steam/sdk64/steamclient.so

Then start the server from anywhere:

/path/to/server/srcds_linux64 -console -game hidden2013 +maxplayers 12 +map hdn_docks

Pterodactyl

For a Pterodactyl panel there's an egg, egg-hidden-rebuild.json (Admin, Nests, Import Egg). A server made from it installs everything above by itself: the SteamCMD server, Beta 4b from its official download, and Hidden: Rebuild. With Auto update on it updates on every start. Release channel picks what it installs: release (the newest release), snapshot (the newest test build) or a release tag such as v1.0.1.0 to stay on it. An edited cfg/mapcycle.txt and your MOTD survive updates.

Outside Pterodactyl, the Linux server package's hidden_update.sh does the same updating: HIDDEN_CHANNEL=snapshot ./hidden_update.sh in the server folder.

Being found

LAN: players on your network see the server under Find Servers, LAN.
Internet: the server registers with Steam's master server by itself, but players can only reach it once UDP port 27015 is forwarded to it on your router (TCP 27015 too, for rcon).
More than one network adapter (VPNs, virtual machines, WSL): the server may pick the wrong one and not be reachable. Add +ip 0.0.0.0 to listen on all of them, or +ip <address> for one.
Listen servers (Create Server in the game) answer on your LAN, and over the internet they run through Steam's relay network instead of your IP, so no ports need forwarding: friends join through the Friends tab or a Steam invite.

Configuring

cfg/server.cfg runs at every map start: hostname, passwords, and the cvars below. Start from cfg/server_example.cfg: every server cvar of the release and its plugins, with its default and what it does. Copy it to server.cfg; updates replace the example, never your copy. Until you have a server.cfg, the server runs the Beta 4b install's. Old Hidden: Source server configs work, including the plugins' cvars.
cfg/mapcycle.txt is the map rotation. The one that ships is Beta 4b's, with the fixed hdn_decay and hdn_origin. Maps the server doesn't have are skipped, and a missing _fixed map falls back to the original.
cfg/motd.txt is the message of the day players see on joining: HTML, up to 2 KB (the engine skips a bigger one), and cfg/motd_text.txt for players who turned HTML messages off. Updates never overwrite them: the packages' own is cfg/motd_default.txt, shown while you have none. A motd.txt in hidden2013/ itself works too.
Bots play both sides: bot_add adds one, hdn_bot_quota keeps the server topped up with them.
Versions: players can only join a server on the same release, so update the server when you update the game.

Cvars

This list is generated from the source code, so it's always the current build's. Server cvars go in cfg/server.cfg; client cvars are for players' own configs. The plugins have their own cvars.

Cvar	Default	Side	What it does
`cl_brasslife`	`90`	client	Seconds ejected shell casings stay on the ground
`cl_hvision`	`1`	client	Draw the Hidden's vision effect when playing the Hidden
`hdn_bot_auto_nav`	`1`	server	Generate a navigation mesh when bots are wanted on a map without one (reloads the map)
`hdn_bot_difficulty`	`1`	server	Skill of new bots: 0 easy, 1 normal, 2 hard, 3 expert
`hdn_bot_forfeit_hidden`	`0`	server	New bots forfeit the Hidden selection (1), so humans play the Hidden
`hdn_bot_join_after_player`	`1`	server	Only fill the quota once a human has joined
`hdn_bot_quota`	`0`	server	Keep the server filled up to this many players with bots
`hdn_deathnotices`	`0`	server	Show the Hidden's kills in the kill feed (the server log always has them)
`hdn_deathwait`	`5`	server	OverRun: seconds before a killed player comes back (four times as long after a marine's suicide)
`hdn_hiddenrounds`	`5`	server	Rounds in a row the same player can be the Hidden before someone else is picked; 0 is unlimited
`hdn_hidehiddendecals`	`0`	server	Keep blood and bullet impact decals off the Hidden; Beta 4b let them show where he'd been hit
`hdn_jointime`	`15`	server	Seconds to wait after a map change before the first round starts
`hdn_limitbombs`	`1`	server	Give the Hidden half as many pipe bombs as there are marines (rounded up), less one, instead of 3
`hdn_radio_limit`	`5`	server	Seconds a player has to wait between radio messages and taunts
`hdn_selectmethod`	`0`	server	How the Hidden is picked: 0 by weighting points, 1 classic (whoever killed the Hidden), 2 random
`hdn_staminadrain`	`-0.095`	server	Stamina the Hidden gains per tick while clinging to a wall; negative, so clinging drains it
`hdn_survivaltime`	`15`	server	OverRun: seconds the last marine standing has to survive
`hdn_targetnames`	`1`	server	Show the name and health of the player under the crosshair: marines see marines ("Friend"), the Hidden sees anyone within 256 units ("Enemy"), as in Beta 4b
`mp_roundtime`	`240`	server	Length of a round, in seconds
`sv_pigstick`	`1`	server	Enables the Hidden's pigstick attack

Commands

Command	Side	What it does
`bot_add`	server	Add bots: bot_add [count] [iris]; 'iris' bots never become the Hidden
`bot_kick`	server	Remove a bot by name, or all of them; 'bot_kick all' also sets hdn_bot_quota to 0
`chooseteam`	client	Shows the personnel selection menu
`classmenu`	client	Shows the personnel selection menu
`hdn_restartround`	server	Restarts the round
`hdn_spec_unrestricted`	server	hdn_spec_unrestricted <name\|#userid> [0\|1]: let a player also watch the Hidden and use the chase and free cameras
`+radiomenu`	client	Shows the radio menu while held
`weaponmenu`	client	Shows the weapon selection menu

Hidden: Rebuild, a community rebuild of Hidden: Source (Calibre Studios, Beta 4b, 2006) on Source SDK 2013. Not affiliated with Calibre Studios or Valve.