Zandronum Server Settings Explained: Game Modes, dmflags, RCON

Q: How do I switch my Zandronum server from co-op to deathmatch?

Set cooperative 0 and deathmatch 1, then load a map with map MAP01 or restart. Mode changes apply on the next map.

Q: How do I become admin on a Zandronum server?

Set svrconpassword, then type sendpassword with that password in the game console and prefix commands with rcon.

Q: How do I let people watch but not play?

Set svjoinpassword and svforcejoinpassword 1. Anyone can connect as a spectator, and only players with the password can join the game.

A Zandronum server is configured with console variables (cvars): sv_hostname, sv_maxplayers and the passwords for the basics, one game mode cvar like cooperative 1 or ctf 1, limits like fraglimit, map rotation with addmap, and gameplay rules packed into number fields called dmflags, zadmflags and compatflags. You can put them in a .cfg file run with +exec, in zandronum.ini, or type them into the server console while it runs. Admin access comes from sv_rconpassword, used in game with send_password.

This page groups the settings by job, with real values you can copy.

Where settings live

There are three ways to set a cvar, and they all end up in the same place:

Method	Format	When it applies
Command line	`+set sv_hostname "Name"` or `+skill 3`	At startup
Config file run with `+exec server.cfg`	`sv_hostname "Name"` on each line	At startup, or any time with `exec server.cfg`
`zandronum.ini`	`sv_hostname=Name` under the console variables section	Read at startup, saved on exit
Server console	`sv_hostname "Name"`	Immediately, until restart unless saved

Command line values beat the ini, so if a setting keeps reverting, check whether the start command is setting it too. On a hosted server, panel fields like max players, skill, start map and the flag values are passed on the command line, and everything else goes in zandronum.ini through the file manager.

Some cvars only take effect on the next map. Game mode changes in particular need a map command or restart.

Identity and access

Cvar	What it does
`sv_hostname`	Server name in Doomseeker
`sv_motd`	Message shown when a player joins
`sv_website`	URL shown to players. Wadseeker also tries it for missing PWADs, so use a page with direct links
`sv_hostemail`	Contact address for players
`sv_maxclients`	Max connections, spectators included
`sv_maxplayers`	Max active players. The rest spectate
`sv_password` + `sv_forcepassword 1`	Password needed to connect at all
`sv_joinpassword` + `sv_forcejoinpassword 1`	Anyone can spectate, a password is needed to play
`sv_updatemaster`	`1` to list the server in Doomseeker, `0` to keep it private
`sv_broadcast`	`1` to announce on the local network

A join password is the friendlier option for a semi public co-op: strangers can watch, friends can play. If your server does not show up in the browser at all, see Zandronum server not showing in Doomseeker.

Game modes

Set one of these to 1 and the rest to 0:

Cvar	Mode
`cooperative`	Co-op, unlimited respawns
`survival`	Co-op with limited lives, set by `sv_maxlives`
`invasion`	Co-op waves of monsters on invasion maps
`deathmatch`	Free for all
`teamplay`	Team deathmatch
`duel`	One on one with a queue
`terminator`	Deathmatch where one player is the Terminator
`lastmanstanding`	Last player alive wins the round
`teamlms`	Team last man standing
`possession` / `teampossession`	Hold the possession artifact
`ctf` / `oneflagctf`	Capture the flag
`skulltag`	Skull based team mode
`domination`	Hold control points

Many gameplay mods expect a specific mode, so check the mod's readme before picking one.

Limits and rules

Cvar	Use
`skill`	0 to 4, from I'm Too Young to Die to Nightmare!
`fraglimit`	Frags to win in deathmatch modes
`timelimit`	Minutes per map. `0` is unlimited
`pointlimit`	Points to win in CTF, Skulltag and Possession
`winlimit`	Rounds to win in LMS and similar
`duellimit`	Duels before the map changes
`sv_maxlives`	Lives per player in Survival
`sv_coop_damagefactor`	Damage multiplier for monsters in co-op

Map rotation

sv_maprotation 1
sv_randommaprotation 0
addmap MAP01
addmap MAP02
addmap MAP03

addmap appends a map, delmap MAP02 removes one, clearmaprotation empties the list and maplist prints it. With rotation on, the server moves to the next map in the list when a map ends instead of following the WAD's own exit. For co-op through a megawad, many groups turn rotation off and let the exits drive progress.

To jump to a map now, type map MAP12 in the console. changemap MAP12 does the same but keeps players' inventory, which suits co-op.

dmflags and the other flag fields

Zandronum packs on/off rules into number fields. Each rule has a value, and you add up the values of the rules you want. Common dmflags values:

Value	Rule
1	No health pickups
2	No item pickups
4	Weapons stay after pickup
64	Stay on the same map when it ends
128	Spawn as far from others as possible
256	Force respawn
512	No armor
1024	Exit kills the player (no exiting)
2048	Infinite ammo
4096	No monsters
8192	Monsters respawn
16384	Items respawn
32768	Fast monsters

So weapons stay plus items respawn is 4 + 16384 = dmflags 16388.

The other fields work the same way:

dmflags2 holds more gameplay rules.
zadmflags holds Zandronum specific rules, such as unlagged hitscan and co-op inventory behavior.
compatflags, compatflags2 and zacompatflags switch on old engine behavior for maps made for vanilla Doom or other ports, for example original sound limits or old movement physics.

The full, current list for each field is on the Zandronum wiki DMFlags page. Doomseeker's Create Game window also has checkboxes for each flag and shows the resulting numbers, which is the quickest way to build a value without doing the math. Set alwaysapplydmflags 1 if some deathmatch rules should also apply in co-op.

RCON and admin control

Set sv_rconpassword "SomethingLong" and restart. Empty disables remote admin.
In game, open the console and type send_password SomethingLong.
Run commands with rcon in front: rcon map MAP05, rcon kick PlayerName "reason".
Log out with rcon_logout.

Useful commands through RCON or the server console:

Command	Use
`kick PlayerName "reason"`	Remove a player
`kickfromgame PlayerName`	Force a player to spectate
`addban 1.2.3.4 perm "reason"`	Ban an IP. Bans land in `banlist.txt`
`delban 1.2.3.4`	Remove a ban
`map MAP05`	Change map now
`say text`	Message everyone

adminlist.txt and whitelist.txt sit next to the config for permanent admins and allowed IPs.

Skip the setup work

On a GamezServers Zandronum server, the IWAD, PWADs, max players, skill, start map and every flag field are panel settings, so you change dmflags in a form instead of a start script. zandronum.ini, adminlist.txt and banlist.txt open in the file manager, and every command above runs from the live console without joining. New to it entirely: start with how to host a Zandronum server, and for more ideas see retro shooters you can still host.

FAQ

How do I switch my Zandronum server from co-op to deathmatch?

Set cooperative 0 and deathmatch 1, then load a map with map MAP01 or restart. Mode changes apply on the next map.

What dmflags value makes weapons stay and items respawn?

16388, which is weapons stay (4) plus items respawn (16384).

How do I become admin on a Zandronum server?

Set sv_rconpassword, then type send_password with that password in the game console and prefix commands with rcon.

Why does my setting keep reverting after a restart?

The start command probably sets it too, and command line values override the ini. Change it where the command line gets it, which on a hosted server is the panel field.

How do I let people watch but not play?

Set sv_joinpassword and sv_forcejoinpassword 1. Anyone can connect as a spectator, and only players with the password can join the game.