In order to configure Dwarf Fortress to your liking there are two files you can edit, init.txt and d_init.txt. The first file, init.txt, contains mostly the settings pertaining to the window, rendering and sound of Dwarf Fortress. The second file, d_init.txt, contains settings that affect game features such as saving and population controls.
 Locating your configuration file
The configuration files are in the data\init folder of the directory that you installed Dwarf Fortress to.
 Editing the configuration file
You can edit the configuration files with any word processing software or text editing software. On Windows, either Notepad or Wordpad will suffice. All data in these files is contained in what are called tokens. Each token is defined by the text between an opening square bracket, '[', and the first closing square bracket, ']'. Arguments to the various tokens are separated from a token identifier by a colon, ':'.
 Settings - init.txt
Change the argument from "ON" to "OFF" to completely remove sound and music from the game. If this is "OFF", it will not be possible to change the volume from the in game options menu.
Changes the default volume of sound in Dwarf Fortress. The argument can be any value from 0 to 255, with 255 representing 100% volume.
 Intro Movie
Change the argument from "YES" to "NO" to turn off the intro movie.
Changes the window mode that Dwarf Fortress runs in. If this is "PROMPT" the game will ask you if you want to run in windowed or fullscreen mode. If this is "NO" the game will be fullscreen with no prompt, and if this is "YES" the game will be in windowed mode with no prompt.
If this is below 256, this specifies the width of the grid used by Dwarf Fortress with a minimum of 80. As such, the width of the window used will be the product of this value and the width of the font used. If this value is 256 or above, it specifies the width of the window used directly.
If this is below 256, this specifies the height of the grid used by Dwarf Fortress with a minimum of 25. As such, the height of the window used will be the product of this value and the height of the font use. If this value is 256 or above, it specifies the height of the window used directly.
The font file that Dwarf Fortress uses. This value can be any .bmp or .png image in the data/art folder.
Can be "YES" or "NO". If this is "YES" you can resize the window while Dwarf Fortress is running.
If this is set to "YES", the window is kept above all other windows.
These settings are used if the [WINDOWED:PROMPT/YES/NO] token is either "NO", or "PROMPT" and the fullscreen option is chosen.
The width of the screen in fullscreen mode. If the value are 0, Dwarf Fortress chooses the best resolution for you.
The height of the screen in fullscreen mode. If the value is 0, Dwarf Fortress chooses the best resolution for you.
The font file that Dwarf Fortress uses. This value can be any .bmp or .png image in the data/art folder.
If this is "NO", tiles will be stretched to fit to the screen if there is a resolution mismatch. If this is "YES", the extra space around the grid is filled with black space and the tiles are left unstretched.
Can be "YES" or "NO". If this is "YES", Dwarf Fortress will use the raw/graphics folder for certain tile graphics. Currently this is limited to creature graphics.
The window width used when Dwarf Fortress is in windowed mode.
The window height used when Dwarf Fortress is in windowed mode.
The font used by Dwarf Fortress when in windowed mode and [GRAPHICS:YES/NO] is "YES".
The width of the screen used by Dwarf Fortress if in fullscreen mode.
The height of the screen used by Dwarf Fortress if in fullscreen mode.
The font used by Dwarf Fortress when in fullscreen mode and [GRAPHICS:YES/NO] is "YES".
If this is "NO", tiles are stretched to fit window in the case of a resolution mismatch. If this is "YES", the extra space is filled with black space and the tiles are left unstretched.
 Video Card Options
This value changes how Dwarf Fortress draws to the screen. As such, changing this value can significantly change the performance of Dwarf Fortress on your computer. Possible values for this are "2D", "2DSW", "2DASYNC", "STANDARD", "TEXT", "ACCUM_BUFFER", "FRAME_BUFFER", "VBO" and "PARTIAL". A technical description of what these do can be found in this post. "PARTIAL" print mode takes an additional argument similar to how the PARTIAL_PRINT value worked in previous versions, with the number representing the number of frames a changed tile is rendered before it is skipped. "TEXT" is only available on OSX and Linux.
If this is "NO" Dwarf Fortress will use double buffering, which may reduce flickering of the screen at the expense of a possible (small) drop in frame rate. If this is "YES", double buffering is turned off.
On video cards that support the OpenGL ARB_sync extension, turning this on can greatly improve performance in GPU overload conditions. However, this can cause Dwarf Fortress to crash on some video cards.
If this is set to "YES", when Dwarf Fortress redraws the screen it will wait for the monitor to finish it's vertical retrace. This can negatively impact your FPS if G_FPS is set high, as the game is forced to suspend calculating game frames to wait for the monitor to finish. The main reason to change this to "YES" is if tearing of the game image occurs regularly for you.
Can be either "LINEAR" or "NEAREST". If it is "NEAREST", the texture values use the nearest pixel value without averaging. If it is "LINEAR", the texture values use the average of the adjacent pixels. In terms of what the two options do to the graphics, the "LINEAR" option will appear to blur adjacent pixels and can result in a fuzzy appearance. The "NEAREST" option will produce a sharp, pixelated look but may result in images looking clipped at some different screen resolutions.
If this is "YES" a FPS counter is displayed on the top left corner.
The game frames per second the game limits itself to. This changes the number of turns calculated per second, not the graphical frames displayed. If this value is 0 the FPS is uncapped.
The graphical frames per second the game attempts to draw. This changes the number of times Dwarf Fortress draws itself to the screen per second. Lower numbers will cause Dwarf Fortress to run faster but skip displaying more game frames between each redraw. To find the number of game frames that are calculated per redraw done by Dwarf Fortress, divide the value for FPS_CAP by the value of G_FPS_CAP. In the default case, this is 100/50=2, so every second frame calculated dwarf fortress will redraw to the screen.
Change this to affect the process priority of Dwarf Fortress. Higher priorities mean that Dwarf Fortress will run faster and other programs will run slower. Possible values are "REALTIME", "HIGH", "ABOVE_NORMAL", "NORMAL", "BELOW_NORMAL" and "IDLE".
 Game Options
How fast the game zooms. A value of 10 corresponds to increasing grid size by 10 units each time you zoom.
[RECENTER_INTERFACE_SHUTDOWN_MS:0] This controls the number of milliseconds that must pass before input works again after the view recenters on an event in dwarf mode.
[COMPRESSED_SAVES:YES] Change this to "NO" if you want to leave save uncompressed. If "YES", saves are compressed in the .zip format to save space.
Determines if the game accepts mouse input.
If the game should display a picture in place of the system mouse icon. The picture lags if Dwarf Fortress is lagging.
The number of milliseconds before holding a key causes it to be repeated.
The number of milliseconds between consecutive repetitions of a held key.
If you set KEY_REPEAT_ACCEL_LIMIT above one, then after KEY_REPEAT_ACCEL_START repetitions the repetition delay will smoothly decrease until repetition is this number of times faster than at the start.
The number of milliseconds between macro instructions.
 Settings - d_init.txt
 Save Behavior
When Dwarf Fortress should automatically save your game. If this is "NONE", Dwarf Fortress never saves your game for you. Possible values are "NONE", "SEASONAL" and "YEARLY".
If this is "YES", Dwarf Fortress will back up your save file each time it autosaves your game.
If Dwarf Fortress should pause the game each time it autosaves for you.
If this is "YES", Dwarf Fortress will save the game immediately after you embark.
 More Game Options
Where to display the number of idlers. The value can be either "TOP", "BOTTOM", or "OFF".
If "YES", Dwarf Fortress starts Fortress mode paused.
Turns on or off temperature. If temperature is off, being adjacent to lava will not cause objects (or creatures) to burn, nor will dwarves have any problems running around on top of glaciers naked if they so desire. Direct contact with lava or firebreath will still cause lots of Fun though.
Turns on or off weather. If weather is off it will never rain or snow.
Turns on or off the fortress mode dwarven economy. This has no effect, since the economy does not function in v0.31.
Turns on or off fortress mode sieges. Turning this off for your first couple of games may make the game easier to start with.
If this is "YES" it is possible for cave-ins to occur.
Turns on or off strange moods and the resulting artifacts.
If this is "YES", when the dwarven economy kicks in all rooms will cost nothing, allowing even the poorest of haulers to have a room fit for a king. This has no effect, since the economy does not function in v0.31.
Turns on or off the testing arena.
Turns on or off the spread of blood spatter and other contaminants between creatures and ground tiles in Fortress mode. As contaminants are buggy and can have a major negative impact on FPS in Fortress mode, it is recommended to leave this set at "NO" for now.
Turns on or off the spread of blood spatter and other contaminants between creatures and ground tiles in Adventure Mode.
The path finding costs associated with different traffic values.
When building a burial receptacle, the option to allow pets to be buried in it will default to NO if this is set to "YES".
If "YES" Dwarf Fortress will display the quality of items in the name. If you get annoyed by seeing items like *<*sword*>* you can get rid of the outside ** by setting this to NO.
If "YES", inspecting engravings and artifacts in Fortress Mode will have an extended history displayed.
If this is "YES", Dwarf Fortress will log the reason why maps were rejected during world gen in the log.txt file.
 Adventure Mode
If you set this to "YES" your adventurer will trigger the traps of your old fortresses
 Embark Options
The size of the default embark site.
The color of body parts when there are no recorded active wounds on the part. Default = white
The color of body parts when there is any damage that doesn't have functional/structural consequences (might be heavy bleeding though). Default = brown
The color of body parts when there is any muscular, structural or functional damage without total loss. Default = yellow
The color of body parts when an important function of the part is completely lost, but the part is structurally sound (or at least partially intact). Default = bright cyan
The color of body parts when the part has lost all structural integrity or muscular ability. Default = bright red
The color of body parts when the part is completely gone. Default = dark gray
The tile and color of areas that are far below the currently displayed z level. The format is SKY:<character>:<foreground color>:<background color>:<brightness>. <character> can be either an ASCII number or a character in single quotes, like '#'.
The tile and color of areas that are far below the currently displayed z level while indoors. The format is the same as for SKY above.
The tile displayed for pillars. Pillars are created at the ends of strings of wall tiles.
If this is "YES" the ground will be varied randomly using the tiles ,.`'. If this is "NO", only the period will be used for ground tiles.
If this is "YES", all engravings are displayed initially looking the same. Otherwise all engravings have a random tile given to them initially.
If "YES" Dwarf Fortress displays water as numbers from 1-7 indicating depth.