Skip to content

Command Line Launch Arguments

This section details the various command line arguments accepted by the client.


The following options can be provided to override values present in settings.json

Number of arguments: 1

Expected format:-settings "/absolute/path/to/settings.json"

Default when omitted: ./settings.json

Example: -settings "/home/tazuo/settings.json"

Function:

Instructs the client to load a specific configuration file.

For more information, please see this page


Number of arguments: 1

Expected format:-username your_username

Example: -username SomeoneAwsome

Function:

Sets the username for the current session


Number of arguments: 1

Expected format:-password your_password

Function:

Sets the password for the current session


Number of arguments: 1

Expected format:-password_enc "your_encrypted_password"

Example: -password "1-DEADBEEF"

Function:

Sets the password for the current session.

Note that the given password must already be encrypted.


Number of arguments: 1

Expected format:-ip "server_ip"

Example: -ip "123.12.12.1"

Function:

Sets the server IP for the current session


Number of arguments: 1

Expected format:-port 0-65535

Example: -port 2593

Function:

Sets the server’s, port (i.e., the destination port the client should connect to) for the current version.


Number of arguments: 1

Expected format:-filesoverride "/absolute/path/to/override.xml"

Example: -filesoverride "/home/tazuo/uofiles_override.xml"

Function:

Allows overriding UO game files.

The file given as an argument will be parsed in a key-value manner (similar to an ini file) with each row representing an overriden file.

An example of such override file could be:

Gumpart.mul=/home/tazuo/gumps/awsome-gumps.mul
skills.mul=/home/tazuo/skills/secret-skills.mul

[!CAUTION] This is an advanced feature. Improper use can cause various issues including crashes


Number of arguments: 1

Expected format:-ultimaonlinedirectory "/absolute/path/to/ultima_online"

Example: -uopath "/home/ultima/ultima"

Function:

Sets the path to the Ultima Online installation directory


Number of arguments: 1

Expected format:-profilespath "/absolute/path/to/profiles"

Default when omitted: ./Data/Profiles

Example: -profilespath "/home/tazuo/profiles"

Function:

Sets the path to the directory holding user profiles


Number of arguments: 1

Expected format:-clientversion "7.0.18.1"

Example: -clientversion "7.0.18.1"

Function:

Sets the client version.

Sent to the server upon entering the world.


Number of arguments: 1

Expected format:-lastcharactername "MyLastChar"

Example: -lastcharname "SirLancelot"

Function:

Sets the last used character name.

Depending on configuration, this option can be used to directly log in select a specific character.


Number of arguments: 1

Expected format:-lastservernum 1

Example: -lastservernum 2

Function:

Sets the index for the last used server.

This argument is used only as a fallback and only when a server cannot be matched by name.

For example, if your configuration specifies server X but server has been renamed to Y, name matching will fail and the client will fall back to the index set here.


Number of arguments: 1

Expected format:-last_server_name "ServerName"

Example: -last_server_name "NowhereInParticular"

Function:

Sets the last selected server name.

Depending on configuration, this option can be used to directly log into a specific server


Number of arguments: 1

Expected format:-fps 60

Example: -fps 60

Function:

Sets the target framerate (Frames Per Second).

The value is parsed as an integer and clamped between 12 and 1000.


Number of arguments: 1

Expected format:-saveaccount true|false

Default when omitted: false

Example: -saveaccount true

Function:

Controls whether account details are saved into the settings file


Number of arguments: 1

Expected format:-autologin true|false

Example: -autologin true

Function:

Instructs the client to automatically continue with server and character selection after the login screen.


Number of arguments: 1

Expected format:-reconnect true|false

Default when omitted: false

Example: -reconnect true

Function:

Controls automatic reconnection upon error


Number of arguments: 1

Expected format:-reconnect_time 5000

Example: -reconnect_time 2000

Function:

Sets the reconnect attempt interval, in milliseconds.

Effective only when reconnect is enabled.


Number of arguments: 1

Expected format:-login_music true|false

Example: -login_music true

Function:

Enables or disables login screen music


Number of arguments: 1

Expected format:-login_music_volume 80

Example: -login_music_volume 80

Function:

Sets the login screen music volume, specified as a value from 0 to 250, where 250 represents full volume.


Number of arguments: 1

Expected format:-fixed_time_step true|false

Example: -fixed_time_step true

Function:

Controls whether the client’s game loop will attempt to use a fixed time step by way of a heuristic algorithm.

[!WARNING] This is feature is experimental and is currently disabled


Number of arguments: 1

Expected format:-plugins "plugin1,plugin2"

Example: -plugins "Razor/RazorEnhanced.exe",ClassicAssist/ClassicAssist.dll

Function:

Sets the list of plugins to load.

Plugins should be provided as a comma separated list of file names (including extension) and the files should be present inside the Data/Plugins folder


Number of arguments: 1

Expected format:-use_verdata true|false

Example: -use_verdata true

Function:

Instructs client to read the verdata.mul and use it to patch the currently loaded game.

This procedure may affect maps, tiles, gumps and so forth.

A valid verdata.mul file must be present in the Ultima Online installation directory.

[!CAUTION] This is an advanced feature. Improper use can cause various issues including crashes


Number of arguments: 1

Expected format:-maps_layouts "MapHeight,MapWidth;MapHeight,MapWidth"

Example: -maps_layouts ""

Function:

Allows overriding default map sizes.

Overrides are provided as pairs of Width and Height, separated by a semicolon (;).

Note that order is important. The first entry is map 0, the next one is map 1 and so forth.

Standard maps are:

  • 0 -> Fel
  • 1 -> Tram
  • 2 -> Ilshenar
  • 3 -> Malas
  • 4 -> Tokuno
  • 5 -> TerMur

[!CAUTION] This is an advanced feature. Improper use can cause various issues including crashes


Number of arguments: 1

Expected format:-encryption 1

Example: -encryption 1

Function:

Instructs the client to use a specfic encryption.

Available options are:

  • 0 -> NONE
  • 1 -> OLD_BFISH
  • 2 -> BLOWFISH__1_25_36
  • 3 -> BLOWFISH
  • 4 -> BLOWFISH__2_0_3
  • 5 -> TWOFISH_MD5

[!WARNING] This is an advanced feature. Improper use can prevent client from communicating with the server


Number of arguments: 1

Expected format:-force_driver 0|1|2|3

Example: -force_driver 1

Function:

Instructs the client to use a specific graphics driver.

  • 1 -> OpenGL
  • 2 -> Vulkan
  • 3 -> SDL/FNA auto-select
  • Any other value -> Default driver

This is also suggested as a workaround if the client crashes on startup with No supported FNA3D driver found! (FNA3D failed to initialize Direct3D 11, Vulkan, or OpenGL) — try each value, update your graphics drivers, and be aware that remote desktop/VM sessions can limit GPU access.


Number of arguments: 1

Expected format:-language RUS|FRA|DEU|ESP|JPN|KOR|PTB|ITA|CHT|ENU

Example: -language ITA

Function:

Sets the UI language.

Accepted values (case-insensitive):

  • ENU
  • RUS
  • FRA
  • DEU
  • ESP
  • JPN
  • KOR
  • PTB
  • ITA
  • CHT
  • Any other value will result in ENU being used

Number of arguments: 0

Expected format:-highdpi

Example: -highdpi

Function:

Instructs the client to treat the graphics output as a “High DPI” device. May improve window sizing and scaling for high resolution monitors.

This setting directly maps into the environment variable FNA_GRAPHICS_ENABLE_HIGHDPI.


Number of arguments: 0

Expected format:-skiploginscreen

Example: -skiploginscreen

Function:

Instructs the client to skip the login screen and connect using the provided credentials


Number of arguments: 0

Expected format:-no_server_ping

Example: -no_server_ping

Function:

Instruct the client to not ping the server during server selection in the login screen


Number of arguments: 0

Expected format:-zlib

Example: -zlib

Function:

Forces usage of the managed Zlib implementation.

See this page for more information.

[!IMPORTANT] The managed implementation generally provides better compatability at the cost of lesser performance



Number of arguments: 0

Expected format:-debug

Example: -debug

Function:

Enables debug mode for the environment.

Can be used to unobtrusivley diagnose certain client issue.

[!WARNING] Debug mode increases the number of logs written and can impact performace


Number of arguments: 0 or 1 (optional)

Expected format:-profiler or -profiler true|false

Example: -profiler

Function:

Enables the profiler. Can be used to unobtrusivley diagnose certain client issue.

Passing no value or an empty ("") one will result in the profiler being enabled.

[!WARNING] The profiler increases the number of logs written and can impact performace


Number of arguments: 0 or 1 (optional)

Expected format:-packetlog or -packetlog "0x1A,0x2B"

Example: -packetlog "0x1,0xA,0xFF"

Function:

Enables packet logging.

When a value is provided only the specified packet types will be traced.

Values should be provided as comma-separated hexadecimal numbers. Provided numbers are trimmed and accept an optional 0x prefix.

Example valid values: 0x1A, 1A, FF.

For more information, see Packet Logging in TazUO


Skips the server select screen if only one server is available.