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STUB Engine Documentation


The Slitherine TUrnBased Engine (STUB) is an engine designed to be flexible enough to manage almost any turn-based game using a tile approach. It uses scripting in a C-style format to manage almost all of the game and UI tasks, and allows for almost every file in the game to be over-ridden on a per-campaign basis. The main components of the system are listed below.


A campaign is the high level package for individual missions. It contains a list of the missions, as well as text files holding campaign specific text.

A campaign can also have a script which can control or provide a basis for higher level logic (e.g. You could have enemy behaviour differ based on the outcomes of previous missions, or hook custom UI into flags denoting abilities for your units).


A campaign consists of one or more scenarios. Each scenario consists of a map file (generated by the built-in mission editor) and an optional script file which deals with all the mission specific scripting of win conditions, enemy behaviour, etc.


The 3D game objects are exported to the game in a custom format. The layout of this format is designed to be as simple as possible to create in whichever 3D package is being used.

These objects are then referenced from the squads.csv file (which can be set up per campaign if desired). The squads file defines various values (known in the system as Attribs). Some are required (such as AP or Action Points) while most will be custom Attribs used by the various scripts you use to define and control your game model. You can also arrange Attribs in arrays which can indexed from inside the script files.

All unit behaviour is controlled by script files. A correctly arranged script file creates the onscreen UI options, controls the unit when the order is given, and gives units information on how to react to other units moving. Each object can have its own script file, or you can share scripts amongst them.


All UI objects are defined using a simple text layout. Every UI object can have an associated script which responds to activation, deactivation, and button controls.

Various script commands allow you to affect UI objects and change their state and contents.


Maps are built from 2 main components. Tiles (used for the ground) and Objects (used for trees, buildings, or anything which is a real 3D object).

Tiles are made up of 2 types, base tiles (which are solid) and overlays (which are alpha-blended). There are multiple layers of tiles available, and tiles can be rotated. It is also possible to build meta-tiles which are more than one game tile in size.

Tiles can also be set at different heights to allow the the construction of simple terrain.

Objects are 3D objects which are placed on the ground. There are various flags which denote how objects affect the tile they are on, such as blocking line of sight, affecting the terrain type of the tile (e.g. adding trees might change the terrain from open to cover), etc.


Bonuses are script files which have special UI hooks which allow them to be allocated to missions in the mission editor. Their scripts control how they look and behave. Examples of a Bonus script might be an airstrike with a cooldown between activations.


Want to jump right in? Want to quickly start trying things out? Just follow these instructions:

  1. Find a campaign directory (e.g. 3Bulge) from the Campaigns directory in the game install, and copy it into your local My Documents\My Games\BBCBA\Campaigns directory.
  2. Copy the Data\Squads.CSV file into the root of your copy of the campaign directory (e.g. My Documents\My Games\BBCBA\Campaigns\3Bulge) .
  3. Copy the Data\Battle\Scripts directory into e.g. My Documents\My Games\BBCBA\Campaigns\3Bulge\Data\Battle\Scripts.
  4. Open the Text1.txt file in your campaign. Change the IDS_CAMPAIGN_NAME string so you can easily pick it out on the campaign list.

Start the game and you should see your new campaign, ready to go! You can now tweak and change these files without breaking or affecting your main game.

You should NEVER change files in the main install directories, this can stop the game running correctly, and also prevent multiplayer games from playing.


Simple Campaigns

To create a simple campaign, which will act as a container for custom scenarios you might make, you can use the in-game editing tools. When you first select the Editor option from the main menu, you will be prompted to create a new campaign. You enter in the folder name (no spaces allowed) which is the sub-folder where all the files for the campaign will be stored. You also enter a name for the campaign, which can be whatever you like – this will be shown on the campaign selection screen.

You will then be taken to the editor screen, and can create and save scenarios as you desire. Go ahead and play with the editor (there are tips shown onscreen the first time you use each control, plus a helper section later in this document). Once you have your first scenario built, save it and you will be ready to test it out through the campaign selection screen.

In a Simple Campaign, the order in which scenarios appear on the scenario selection screen is not defined.

Advanced Campaigns

If you want to control the order in which scenarios are listed, set up custom text for scenarios, or customise any other aspects of the game when playing your scenarios, you will need to edit additional files. Editing these files is easy, and their contents are explained below.


This file denotes the order of any campaigns that are included on the scenario selection screen. Note that if this file does not exist, then the game will attempt to use all the scenarios in the SCENARIOS directory.

The form of the file is simply:



Where the scenario names are the filenames of your user scenarios. So in this case you would have Scenario1 and Scenario2 BSF files from the editor.

Custom Text

You can have multiple text files inside the campaign directory. They must all be named TEXT<N>.TXT where N can be any number from 0 to 63. For example text0.txt or text12.txt.

These text files must be UNICODE files, and so support non-ASCII characters [Note: you may need to use applicable fonts to allow the display of non-ASCII characters].

The built in Notepad application in Windows allows you to save UNICODE text files.

The format of these (and all) strings files is:

<stringTag>, “<string>”,

The commas are important! Note that to insert a newline into a string, you need to use the ~ character.

Strings used by the game are:

IDS_CAMPAIGN_NAME, “The campaign name shown on the campaign selection screen”,

IDS_SCENARIO_DESC_<scenarioName>, “one string per scenario, shown over the scenario selection display if there is no custom UI for the scenario (see below)”, 

IDS_CAMPAIGN_TEXT, “Text describing the campaign, shown on the campaign selection screen if there is no custom UI”,

Some of these strings are set up for you when you create the campaign, others you can add if you want to have more customised text shown when people play your campaign.

Campaign Graphics

There are two files you can create to customise the look of your campaign. These files can be in either TGA or DDS (recommended) format. If either of these files are not defined, then the game uses some default images. 1024×1024 or 512×512 are usual sizes for these two images.

Note: All image files and textures you create for the game should be square and with sizes which are powers of 2 (32,64,128,256, etc), and ideally no larger than 1024×1024.

BACKDROP.DDS (or TGA) This file is used as the backdrop behind your scenarios after you select your campaign to play.

ICON.DDS (or TGA) Shown on the campaign selection screen. The image should be alpha blended (that is, transparent) and should only use the right hand 55% of the image (as it is extended across the whole screen, and should avoid going under the campaign list).

Campaign Scripts

If you create a CAMPAIGN.BSF script file, then it will enable you to have campaign-level logic which you can then deal with within your battles.

Campaign scripts make use of campaign variables, which are special global variables defined in the CAMPAIGN.TXT file. To define a campaign variable, you need to add a line of the form:

VAR <name>

for example

VAR TotalKills

You can then use the SetCampaignVar and GetCampaignVar commands any scripts that you use, including any campaign script. You are limited to 64 campaign variables, although each one can be accessed as an array of 8 entries (see the documentation for Get/SetCampaignVar for more details).

Campaign Script Callbacks


Many times we want to be able to respond to events from within the game. The game uses callback function to do this. These are specifically named functions which are passed information by the game.

You can define certain campaign functions which will be called when specific actions happen in the game. They are:

// Called whenever a unit is destroyed.
// called every time a campaign is loaded up.   
// Note:  Not just when a new campaign is started.


You can create your own campaigns entirely from within the game, but you can also create custom text and images to change the look of your campaign.

You can also create custom UI, animated briefings, custom units, and even give units entirely different behaviours! How to do this is described in upcoming sections.


Without a special script, a scenario will end once all of the enemy's units are destroyed. But a scenario script allows you to have much finer control of the course of a battle.

The Scenario Script

The scenario script interacts with the mission through a number of callback functions.


// Called every tick

This callback is called every tick of the model (30 times a second). The side is the side currently having its turn. Use this function to track ongoing events, like the death of units, or movement of the enemy.


// Called at the beginning of each turn

At the start of each new turn, this function is called. The mode parameter describes the type of game in progress (e.g. single player, PBEM, etc), and is generally not needed. Use this function to trigger events based on the turn.

Note that this function is called once per turn, and the sequence of turns is as follows:

-1 : This is a pre-turn called when a scenario is first begun 0 : First turn for side 0 1 : First turn for side 1 2 : Second turn for side 0 3 : Second turn for side 1 4 : etc


// Called after all the default start turn logic has been done

After the StartTurn function is called, there is other internal logic which occurs (for example, updating the APs for each unit, and calling any unit script functions). This function can be used optionally to make changes once all the normal logic and value resets are done. And example is altering the default sight ranges, or number of APs a unit has.


// Called each tick.   Can determine whether there is a winner for the scenario.

This callback if called every tick provided no winner has been selected. The code passes in the side it thinks is the winner (-1 for no winner yet). It returns a new winner value. 0 or 1 for a winning side, and -1 for no winner. Thus it can prevent the default game logic from ending a battle should it need to.

Note that this function is no longer called once a winner is set in any way (e.g. through the EndBattle command).


// Called every frame to render out any scenario specific UI

You can use this function to render any custom UI which your scenario might desire. Examples would be tracking achievements (see below), showing a turn countdown if there is a limit in the mission. But it could be anything you like using the UI script commands (see the list of script commands).

Note that this display can be disabled by the user using the toggle which appears just below the Exit Battle button whenever this function is defined in the scenario.


Achievements are special events that you can tell the game to look for and congratulate (or berate!) the player. Examples would be for numbers of kills in a timeframe, or before some other event has happened. They are very simple to set up. Here is an example (it is the code used in the tutorial to congratulate you for killing your first enemy):

	// did we kill the only unit on the enemy side?
	if( GetUnitDead(1000) == 1)
		// pop up some UI to tell the player
		AddVizFunctionCall("ShowUIScreen", "BattleHead0", 
                                    "Anim1", "IDS_T1_A1","BHead0Image:achievement_star");
		// return 1, tell the game we got the achievement		
                return 1 ;
	// otherwise return 0 to tell the game to keep checking
	return 0 ;

You create an achievement by adding a function to your scenario script which has a name which begins with ACHIEVEMENT_ and then adding some logic to return 0 when it has not been achieved, and 1 once it has (at which point the game will stop calling to check).

The game looks for a string called IDS_ACH_<name> to use as the tooltip on the stars which appear on the Force Selection and Results screens. So for the above example, the string would be IDS_ACH_FIRSTBLOOD.

The game also automatically creates a global variable which holds the current achievement state. It is made up of an upper case version of the achivementname, with a g prefix. So in the case above you could use


to determine whether the achievement had been gained or not in a mission script. The global starts with a value of 0, and is set to 1 when the achievement is gained (e.g. when the achievement function returns 1).

Unit Scripting

The ability to alter the behaviour of the units is one of the most powerful areas of the game scripting. Each unit type can have its own set of scripts and behaviour (although you don't have to do this). As you will see, you can get units to do almost anything with a well written script.

A unit will look for a script which is called <name>.BSF in the DATA\BATTLE\SCRIPTS directory in your My Documents campaign directory, where <name> is the unit name as denoted by the Name entry in the squads.csv file. If the code cannot find a unique BSF file, it will load up a script called $DEFAULT.BSF to handle all the unit's behaviours.

The approach that the game itself uses is to have all units use a single set of scripts, but to use the unit attributes (as defined in the squads file) to determine what a unit can or cannot do. This has the advantage that abilities can be added or removed from a unit simply by altering data.

On the other hand, you might have units with very disparate abilities, in which case you might be best using individual scripts for each unit, bearing in mind you can always INCLUDE any shared functionality.

Unit Callback Functions

There are a variety of functions which a unit can have which are called at times by the code.



This function is called at the start of a unit's side's turn. This would be used to reset any per-turn counters or limits. Examples would be a unit's shots, or tick up its morale. STARTTURN is a required function for every unit.



The custom trigger is a low level function used to trigger scripting from the unit animation files. It passes through any of the 4 parameters allowed in the animation file for a unit.

Init Functions


Any function which is named with INIT_ as the first 5 characters will be called on unit creation. You can use this to set up attributes, initialised starting values, etc. Note that if there is more than one INIT_ function then the order they will be called in cannot be guaranteed.

Unit Ability Functions

To actually allow a unit to do anything, it needs to have scripted behaviours. An example can be seen in the Case Study at the end of this document, but the key functionality is described below. Once again we also recommend reading through and editing (in your own custom campaign, never in the main game data!) the existing unit scripts to see how it all hangs together.

There are 3 types of ability, depending upon the contents of the tile you are attempting to action. These are TILE_, ALL_, and UNIT_. TILE_ can operate only on empty tiles, ALL_ will attempt to work on all tiles, and UNIT_ will only operate on a tile with a unit present on it.

The key functions which will allow you to begin creating unit behaviours are described below. Note we will show all examples using the ALL_ tag, but this can be replaced with the TILE_ or UNIT_ tag to simplify the scripting as desired.

Note that for all the functions described here, you can omit any of the parameters you don't use, and that the code will correctly assign them no matter where in the param list they are. Indeed, you can have extra parameters in a function header and they will be set to zero if they are called by the code rather than by you.


FUNCTION CHECK_ALL_<name>( me, unit, tilex, tiley [, reaction] )

This function is used to determine whether a unit can perform a task. The return value can be either the cost of the action in AP, or -2 if you with the task icon not to be shown, or -1 if you wish to show the icon in a disabled state. See below for details on the optional reaction parameter.

Icon Setup

FUNCTION UISETUP_ALL_<name>( x, y, width, height, me, tilex, tiley )

This function can be used to setup and draw the order icon. The x,y,width,height parameters are the onscreen positions of the button.


FUNCTION ALL_<name>(me, unit, tilex, tiley)

This is the function which is called when the user selects the action for the unit. Note this cannot happen if the check function returns -1 or -2 as the icon will not be selectable.


FUNCTION REACT_ALL_<name>(me, unit, tilex, tiley)

If you want a unit to be able to react to other units, then you make use of the reaction function. This works in concert with the CHECK_ function for a given command. The system first calls the CHECK_ function to determine whether an action is possible against the reacted-against unit. Note that when CHECK_ is called in this case, the optional reaction parameter is set to 1, rather than 0 as it normally is.

If the check function returns >=0 then this is taken as the AP cost of the action, and the system then calls the REACT_ function. The react function should return a 'score' for this unit using this action to react to the threat. Examples of how to calculate this score we be based on things like chance of success, range to target, etc - as dependent upon the game model. The system will go through all units on the reacting side and then sort the reactions by their scores, and execute them in the 'best' order. Note that returning -1 from a REACT_ function means that you do not want the unit to attempt to react with this action.

Scripting Reference

Script Syntax

CScript is a simple scripting language, based on the basic C syntax. It provides a simple framework to hook it up to an application, effectively the function call handling.

Even if you have not had experience with scripting languages before, you can begin to add or alter your custom scripts using just a simple text editor (see the Tools section for details on how to help make editing better with syntax highlighting and other useful features).

The team recommend taking a look at the existing scripts to begin to see the way the scripting works. Beginning by tweaking existing scripts is a great way to see something onscreen quickly.

All scriping must be part of a function. A function has the form:

FUNCTION <name>( [<param>], [<param>], ...)
	<function body>

for example

FUNCTION Tick( side ) 

there is a limit of 8 parameters that can be passed to a given function.

All functions return a value, although you do not have to use it, nor use the return should you decide not to. To return a value use:

	return <value> ;

Note that a call to return will skip any further processing in the function and exit with the value immediately.


You have 2 ways to control the flow of a function. The IF statement, and the FOR statement. All code executed by an IF or FOR statement must be enclosed in a block (within a { } pair).

An IF statement has the form:

	if( <condition> )
		<execute if condition true>
		<execute if condition false>

Note that the else keyword and following code is optional. Where the condition can be made up of various logical operators such as && (and) and || (or). So an example statement would be:

	if( ( a == 10) || ( b == 5 ) )

Note that CScript does not have robust bracket handling, and so if you have complex conditionals it is generally best to construct them in a sequence of IF statements.

A FOR statement has the form:

	for(<start>; <condition>; <delta>)

<start> is a statement initialising the loop variable, <condition> is a check where the loop will continue so long as it is true, and the <delta> statement is a simple expression incrementing (or decrementing) the loop variable. So the statement:

	for( i=0; i<10; i++ )

would repeat the code inside the block with i having values of 0 to 9 inclusive, before moving onto any following code.

Key Differences with C

There is no operator priority. Expressions are parsed left to right. Brackets are supported and their use recommended.

IF statements can can use only a single && or || statement pair when expressions are not contained in brackets. That is:

	if( a == 0 && b == 0 && c == 0 )		is invalid
	if( (a == 0) && (b == 0) && (c == 0) )		is valid

There is no concept of ELSE IF(…) in the language. You can only pair a single ELSE with any IF statement.

FOR statements do not allow bracketed terms in the increment (3rd) expression. That is:

	for( a = 0 ; a < 10 ; a += (10 – c ) )		is invalid

All variables are signed integers.

String expressions are only allowed as input to function calls. Currently there is no string manipulation functionality.

Single line IF and FOR result expressions are not allowed:

	if(a == 0)				is invalid
		a = 10 ;
	if(a == 0)				is valid
		a = 10 ;

Including Files

You can include other files in your scripts. These can contain useful utility functions, either of your own, or from the game. The syntax for including a file is:

include "filename.bsf"

The script system will look for the file in the following places in the following order:

same folder as the initial file
<campaign folder>/DATA/SCRIPTS

Case Study

Here is a quick example to show how the system works. We are going to add a new command to our units. We assume that this new script file has been included in a larger script which applies it to our units. (e.g. the $DEFAULT.BSF file which is used by any units which cannot find a custom script file).

// Turn and face a tile
// This is the function which actually does the work when we want to activate the
// ability.  The ALL_ prefix tells us we can do this to any tile we like.
FUNCTION ALL_TURN(me, tilex, tiley)
	AddVizUnitTurnToFace(me, tilex, tiley) ;
	if(GetUnitTurret(me) == 1)
		// turn the turret to face the target as well.
		AddVizUnitTurnToFire(me, tilex, tiley) ;
// This CHECK_ function tells the UI how and if to display the option to the user
// when we are over this tile.  The unit param is either the index of any unit on
// the tile, or -1 if there isn't one.
// CHECK_ functions return the cost of the action (0 or more), or -1 to show the action greyed out (disabled), and -2 to not show the option at all.
FUNCTION CHECK_ALL_TURN(me, unit, tilex, tiley) 
int ret ;
	ret = 0 ;
	// only allow it to work for tiles <=3 from us
	if( GetDistanceFromUnit(me, tilex, tiley) > 3)
		ret = -2 ;
	return ret ;
// This is how we control the UI for the onscreen button.
	// Begin to construct a string
	StartString() ;
	PrintStringLiteral("Turn") ;
	// Now set that string as a tooltip
	SetUITooltip() ;
	// finally define the button texture and colour
	SetUITexture("action_turn", "ffffffff") ;
// This function would allow us to do any custom drawing etc on the button as it is shown
FUNCTION UIBUTTON_ALL_TURN(me, x,y,width, height, tilex, tiley)
	// we don't want to show anything fancy this time!

Creating 3D Models

To create 3D models, you will need access to the MAX modelling software, as well as a paint tool to create the model textures. Before you begin, you will need to download the 3D starter pack from


this contains the exporter script, as well as a couple of example units to give an idea of how to construct them.

[Note: we are currently in the process of creating exporters and example assets for other 3D modelling packages. If you have a favourite one which isn't supported, let us know on the forums!]

Installing the Exporter

  1. place the file in the Scripts\Startup folder inside the MAX install folder.
  2. start MAX and go to Customize → Customize User Interface.
  3. select the Toolbars tab.
  4. in the Catagory dropdown select the SlitherineTools category.
  5. drag the Export S3F entry onto your toolbar.

Using the Exporter

The exporter will export only the selected objects in the scene. When dealing with skinned objects (such as infantry) you should not select the bones, only the meshes. This is because the exporter uses a per-vertex export method, meaning you can animated the meshes any way you want.

You should then use the dialog to set which meshes are static (that is, do not deform, such as tank turrets, etc) and those which do (such as an infantry skin).

Finally export to an S3F file. This file can be read in by the game.

[Note: when you run the game it will recode any S3F files into S4F files, the binary equivalent, which are much faster to load. It will then load this file from then on. So if you are tweaking the S3F file, you will need to ensure you delete the S4F to see changes in the game. A batch file can be helpful here.]

Adding Assets to the Game

There are 2 main 3D components to the game, objects and units. We will explain how to use both.

Texture Flags

You can add special characters to your texture names to enable specific functionality.

Including a @ symbol in your texture name will enable alpha-keying when the texture includes an alpha channel.

Including a & symbol in your texture name will prevent the texture being lit, and it will always be drawn using it's own colours without any lighting added.


To create a custom object set, you must:

  1. create an OBJECTS folder inside your custom campaign.
  2. create a folder for each object set you wish to create. Usually one will be enough for a given environment, and can contain many objects.
  3. Build you objects and export them into the folder you have created. Object names should not have spaces in them. The object texture should go in this directory too. Each object can only have a single texture applied to it, although objects in a folder can of course share a single texture (this is recommended for performance).
  4. Create the 3 state textures which are needed. These are all named based on the name of the texture applied to the object (which should be its 'normal' state texture). The 3 additional textures required are detailed below in State Textures.
  5. Set up any object data. Objects without any data are fine, and will just sit on the map. But you can define various behaviours for them by creating an entry in the OBJECTS.TXT file. The entries are detailed below in Object File Entries.

State Textures

FOW		name_M.DDS
Required to show the object when it is not revealed

Damaged		name_D.DDS
Only needed for objects which can take damage (see below)

Damaged FOW	name_D_M.DDS
Again, only needed for objects which can take damage

Object File Entries

BLOCKING			object blocks LOS
HIDEDAMAGE		don't show damage on the tile when this object is applied 
EDGE			object goes on tile edges (e.g. hedgerows)
HIDES			object is not shown until tile is revealed
FADE			should object fade when a unit is on the tile
RANDROT			place the object with a random rotation
PLACEMENT		limit object placement around the tile center.  Values should be between 0 and 16.  Smaller values force toward the center of the tile.
HEIGHT <float>		object height (e.g. used when placing the ?)
UIHEIGHT <float>		does the object lift the UI tile display (e.g. bridges)
CLUSTER <float>		do units cluster near the center of the tile.  Must be 0 to 1 inclusive.  Smaller numbers cluster towards the center of the tile more.
RANDSCALE <float>	randomly scale up the object when placing.  E.g. A value of 1 would scale the object between its original size and 2x its size.
DAMAGE <byte>		amount of tile damage which will cause an object to show as damaged
TERRAIN <string>		placing this object will set the terrain type of the tile to this

If the filename of your object is building.s3f, then the chunk header would be


followed by any data lines you wanted to use. Check out the OBJECTS.TXT files in the main game folders for examples.


Building a Unit

When building a unit, there are a few special object names and characters to know.


You should name the main turret object of any unit with a turnable turret with this name. The game will then rotate it horizontally as needed.


Placing a # as the first character in an object name will make it invisible


If the code finds a ! in an object name, it will attempt to read the following characters as a number. This number is assumed to be an emitter for various particle effects used in the game. E.g. !0 would define the object as being emitter 0. You will see many objects in the example models with names like #!0 which denotes them as hidden emitter objects.

You should use the example units as templates for which emitters are used. The particle effect editor is currently not ready for use outside the team, but will be coming soon!


All unit animations need to be included in a single file. The animations will be defined in a text file which will also trigger fx, sounds, etc. There is no fixed order required for animations. All animation will be played back at 30 fps in the game.

Once your unit is built and animated, you should export it to an S3F file. This file need to be placed into a DATA\BATTLE\UNITS folder in your custom campaign. Its texture should go into a DATA\BATTLE\UNITEXTURES folder in your custom campaign directory. A unit can only have a single texture applied to it. If you wish to have a dead texture for the unit, it should be named as per its main texture, but with _D appended, e.g. A unit with MYUNIT.DDS would use a death texture of MYUNIT_D.DDS.

To set up the animation file for a unit, you need to create a text file inside the DATA\BATTLE\UNITS folder which has the same name as your S3F file, e.g. If your unit is called MYUNIT.S3F, then you create MYUNIT.TXT.

[Note: This is slightly simplified. Specifically, for technical reasons, you would need to name the S3F file MYUNIT_0.S3F (that's a zero). But the TXT file and the entry in the assetfilename slot of the SQUADS.CSV file would still remain MYUNIT.]

Inside the TXT file, you need to set up an entry for each animation you want the unit to use. Most animations will be triggered from the scripts, but two are assumed to exist. These are WAIT and MOVE. You can have multiple animations for a give action, and the code will pick randomly from them when it wants to use an animation. The basic layout for an animation entry is:

[<anim><index>]		the index must be a 2 digit number, in sequence, starting at 00, e.g. WAIT00, WAIT01, etc.
FRM <start> <end>		required; the start and end frames of this animation
FX <frame> <effect>		trigger an effect at this frame
DIETEX <frame>		switch the unit's texture to its dead version
CALL <frame> [<a> <b> <c>]	call the unit's CUSTOM_TRIGGER callback, passing in the supplied parameters, all of which are optional and dependent upon the callback function.
AMBIENT <a> [<b> <c> <d>]	play a sound effect constantly while this animation is active. The entries are the ID values of the sound effects (as defined in the sfx*.txt files).  Picks randomly if more than one defined.
SFX <frame> <a> [<b> <c>]	play a sound effect at this frame, pick randomly if more than one is defined.

Examine some of the existing unit .txt files for examples of how these files are laid out.

Once you have your unit data set up, all you need to do is set the assetfilename entry in the SQUADS.CSV file inside your custom campaign, and it will make use of the new asset.


Grab these free tools to make editing files simple and easy.


You can grab this awesome free editor from


Download and install the app, then set Notepad++ as the default application to open *.BSF files. Then run Notepad++, and go to Settings→Style Configurator…

Click on the C entry in the Language: list, and then enter BSF in the User Ext.: box.

Now simply specify Notepad++ as the default application to open .BSF files and you have an editor which will highlight syntax and also tell you when brackets are missing, along with being awesome.

Open Office/Libre Office

Open Office or Libre Office allows you to open and edit the CSV file used for the unit data. You can download it from

http://www.openoffice.org/ http://www.libreoffice.org/


Custom Campaign Folder Layout

Here we describe the folder and file layout of all possible entries you might want to have in a custom campaign.

Not all the files listed here are required, in fact most are not needed to build a simple campaign, but this is included to provide an aid to correct placement of the files needed to add a given feature to your campaign.

│   backdrop.dds
│   Campaign.txt
│   icon.dds
│   sides.txt
│   Squads.csv
│   Terrain.txt
│   text1.txt
│   uniticons.dds
│       AI.bsf
│       MyAnim.s3f
│       MyBonus.BSF
│       cards.txt
│   │   music.txt
│   │   sfx0.txt
│   │
│   ├───BATTLE
│   │   ├───SCRIPTS
│   │   ├───UNITS
│   │   │       MyUnit.txt
│   │   │       MyUnit_0.s3f
│   │   │
│   │   └───UNITTEXTURES
│   ├───MUSIC
│   ├───SOUNDS
│   └───UI
│       │   Campaign_Overlay.txt
│       │   EndCamp.txt
│       │   SCENUI_MyScenario.txt
│       │
│       └───TEXTURES
│           │   CampaignListIcon.dds
│           │
│           └───ICONS
│                   MyUnit.dds
│                   MyUnit_SLOT.dds
│       MyScenario.bam
│       MyScenario.bsf
│       MyScenario.dds

Scripting Commands

A list of all built-in scripting commands is generated by the game into the AUTODOCS directory in My Documents\My Games\BBCBA (~/Documents/My Games/BBCBA on Mac), and so that file will always be up to date, but it is repeated here for ease of access with the other documentation.

Script Command List

stub_engine.txt · Last modified: 2020/11/01 00:59 (external edit)
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