Creating VASSAL Modules (written for VASSAL 3.1, but still generally useful)

jrwatts · July 20, 2025, 3:39am

Note: This is copied verbatim from the old wiki; not sure who the original author (referenced as “I” in the text) is.

Creating VASSAL Modules

Re-organization of this FAQ section

Starting to get a bit long here, I plan to re-organise this page into
sub-pages. Suggest categories:

Questions about Maps and Grids.
Questions about Counters and traits.
Questions about decks (or does this overlap counters?)
Graphics and image questions (overlaps with maps & grids?)
General Questions

General

I want to make a module for such and such a game. Am I allowed to?

Legally, to post a module onto the VASSAL site you need the permission
of the copyright holders of the original game. Many module creators now
try and identify and contact the copyright holders and ask for
permission. This can be difficult at times.

Theoretically, if you create the module for your own use and for
distribution to only people who you know also own the game, then you
possibly do not need permission. This point of view is open to argument.

If no response is received from the copyright holders, or they cannot be
identified, an often followed course of action is to inform the
copyright holders (as best you can), that you accept their silence as
tacit approval and post the module for general distribution, with the
understanding that the module will be removed should the copyright
holders wake up and request it to be removed. Rodney has a policy of
removing modules from the VASSAL site when requested by the copyright
holder.

Is there a Module size limit?

No. In Vassal 3.1 a module is not limited by size on a disk. A module is
limited by memory space available in RAM only. In general, the graphics
used in a module are the biggest driver of memory usage requiring 4
bytes per pixel for each image that is currently being displayed.

For example:

A map measuring 2000x3000 pixels is displayed with 20 counters on
the map that measure 50x50.
Total Memory required equals (2000 x 3000 x 4) + (20 x(50 x 50 x 4))
= 24,200,000 bytes or 24mb (approx)

Map Problems

How do I align the Vassal hex grid with my scanned mapsheet?

These descriptions assume the grid is sideways. Slightly different
procedure for a normal grid.

Work on one axis at a time.
Draw the grid and center dots in red so they stand out.
Change Hex height up/down bit by bit until the grid hexes are
approximately the same width as the map hexes.
then adjust the y offset to get them lining up closely.
then fine tune the hex height. Look at a couple of hexes, are the
red hexes slightly bigger or slightly smaller? Look at the pattern
over a few hexes to tell for sure.
Fine tune the y offset.
Up till now, completely ignore the x offset and hex width.
Now with the Hex height and the y offset set, use the same procedure
on the Hex width and the x offset. Leave the Hex height and y offset
unchanged while you work on the Hex width and x offset.
Adjust the Hex width until you get a repeating pattern showing the
hexes are about the same size.
Adjust the x offset to get the pattern in the right place.
fine tune.

The key is to always adjust the Hex height and y offset first and get
that right before doing anything with the width and x offset.

I have an Area Movement map, how can I implement that in vassal?

To implement an Area Movement map, use an ‘Irregular’ grid on your Map
boards. An Irregular grid allows you to place named points (termed
‘Regions’) anywhere on the map board. These named points will act like
the cell centre points on hex or rectangular grids. Units can be made to
snap to the nearest named point. Unit location will be reported as the
nearest named point.

For maps with very irregular shaped areas, you may need to specify more
than one point in each area, each with the same name. These additional
points will be invisible if you turn the ‘Snap to grid points’ and ‘Draw
region names’ off.

It is also possible to implement an Area Movement map using Zones drawn
to cover the map areas. This method is not recommended for large numbers
of Zones.

How can I have areas on my map with a different Grid setting?

Multiple Grids are added using Zones. Grids are added at the Board
level, not the Map level, so need to be set on each Board that makes up
your map. Follow this procedure for each Board:

First create a ‘Multi-zoned Grid’.
Next, create your standard Hex, Rectangular or Irregular grid that
covers most of the board. This is the ‘default’ or ‘background’ grid
that will be used for all areas of the Map not covered by a Zone.
For each area of the Board that is to have a different Grid, create
a Zone. Don’t click the ‘Use Board’s grid’ button as this will force
the Zone to use the grid you specified in step 2.
Right-click on the newly created Zone and you can now add a Hex,
Rectangular or Irregular grid that will apply only within that Zone.
If Zones overlap at a given point, the Zone defined first in the
module will take precedence at that point.

How do you stitch scans together to form a single image?

After scanning a large boardgame, how do you stitch the scans together
to form a single image in order to install it on vassal?

You can do this using any graphics program such as Photoshop or Gimp
that allows you to rotate and align images. There is also “Hugin”, a
specialized program for stitching together scanned images:
http://hugin.sourceforge.net/tutorials/scans/en.shtml

Trait Problems

Why doesn’t trait X work correctly?

See next entry.

How come the mask trait doesn’t hide Y?

The most common reason that a trait doesn’t affect things the way you
expect it to is because it isn’t in the correct order in the traits
list. Many messages reporting bugs and module problems stem from the
same basic misunderstanding about the way that counter traits work.

The Three most important things to remember when setting up traits in a
counter are

LOCATION, LOCATION and LOCATION!

The order of traits is VITALLY important. This needs to be engraved on
the forehead of every budding VASSAL module designer.

Each trait is only affected by other traits that are BELOW it in the
expanded list of traits after taking prototypes into account.

If you want Text Labels to Rotate, then the Text Label trait must be
ABOVE the Rotation trait. If you don’t want your Text Labels to rotate,
then they must be BELOW the Rotation trait. You need to think about each
trait, how it affects the counter and whether it should affect, or be
affected by, other traits that affect the counter.

This is a FEATURE, not a BUG. You can’t just blast in the traits you
want in any order and expect them to work. You can’t move a trait from
one prototype to another and expect it to work in exactly the same way
(though it may). You need to take into account the order of all traits
in all prototypes after they have all been expanded.

Thanks to Brent Easton

My Rotate trait is not rotating all of my layers, what’s wrong?

You probably have a problem in the order of the traits defined in your
counter.

The order of the Traits in a counter is vitally important in vassal.
This is a very important aspect of the way the Vassal works. Any given
Trait will affect all other traits above it on the list, but does
not affect any traits below it on the list. See previous entry.

Why do I get large selection boxes when using Masks and Movement Trails?

Because the Mask is being applied to the Movement Trails, which generate
a bounding box to cover the entire trail. Moving the Mask trait above
the Movement Trail trait on the trait list should cure this problem.

How to restrict access to a trait while allowing drag’n’drop operations on the gamepiece?

Basically a restricted access trait affects all traits above it.
However, the gamepiece’s drag’n’drop mechanisms do work differently:
They honor the bottommost restricted access trait. Here’s a solution
that works for the Downtown module:

Basic Piece
Trait to be protected
Restricted Access - Side(s) that may use trait
Restricted Access - All Sides that may move the gamepiece

How can you alter the location of the “masked” icon?

When using the mask trait, the masked icon normally appears in the
center of the graphic of the masked counter or card. If you want it to
appear elsewhere, then create a mostly transparent graphic the same size
as the counter or card with the mask in the location that you want it to
appear.

Thanks to Dr. Nostromo

Properties

What ‘system’ properties are returned by counters?

The new Properties Filter in the GlobalKeyCommand allows you to select
units based on Marker properties. Are there any ‘system’ properties that
counters return that can be used in the same way?

All counters will return the following properties:-

BasicName: Name of the piece recorded in the BasicPiece trait.
CurrentBoard: Current Board name or “” if not on a map.
CurrentMap: Current Map name or “” if not on a map.
CurrentX: Current X Map co-ordinate of the piece.
CurrentY: Current Y Map co-ordinate of the piece.
CurrentZone: If the current map has a multi-zoned grid, then
return the name of the Zone the piece is in, or “” if the piece is not
in any zone, or not on a map.
DeckName: Current Deck name, or “” if not in a Deck.
IgnoreGrid: “true” if this piece ignores the map grid.
Immobile: “true” if this piece is an immobile Terrain piece.
Invisible: “true” if this piece is Invisible to the current
player.
InvisibleToOthers: “true” if this piece is Invisible to other
players.
LocationName: Current Location Name of piece as displayed in Chat
Window.
Moved: “true” if the piece has moved.
NoStack: “true” if this piece does not stack with other pieces.
Obscured: “true” if this piece is masked to the current player.
ObscuredToOthers: “true” if this piece is masked to other
players.
OldBoard: Board name prior to last movement.
OldLocationName: Location name of the piece prior to last
movement.
OldMap: Map name prior to last movement.
OldX: Map X co-ordinate prior to last movement.
OldY: Map Y co-ordinate prior to last movement.
OldZone: Zone name prior to last movement.
PieceName: Full name of the piece as reported in the Chat
Window.
playerSide: Side of the current player (not side of the piece).
Restricted: “true” if there are restrictions as to who can access
this piece.
Selected: “true” if the piece is currently Selected.

Different counter traits will also return properties:

PropertySheet:

<property_name>: The value of each property on the Property Sheet
can be accessed via the property name.

Layer:

_Active: “true” if the Layer is currently
active.
_Image: The Image Name of the currently active layer for
Layer .
_Level: The level number of the currently active layer for
Layer .
_Name: The Level Name of the currently active layer for
Layer .

Can Rotate:

_Facing: The Current Facing number (1, 2, etc.) for the
Can Rotate trait .
_Degrees: The Current Degrees of rotation for the Can
Rotate trait .

Decks also have map-level properties that you can reference:

_numPieces: The number of pieces in the deck .
_<expression_name>: The number of pieces for which the
named expression evaluates to true in the deck .

When Do I Need “$” in Property Comparisons?

Have a look at the example in the reference manual:

Hitpoints_Level < 2 && Wound_Active != true

No $ signs. The left side of the comparison is always treated as the
name of the property. So it doesn’t need $ signs.

You use the $ signs in two situations:

1. To compare a property to another property, use the $ signs in the
second (right side) part. The $ signs are needed to show that you want
the value of a property rather than testing against a literal string.
For example:

Rand5_result = $Another_property$

2. To use indirection, where one property contains the name of a
property to compare. If the property “prop1” has a property name as a
value, then to compare the value of the property contained in “prop1” to
a value, use $ on the left side:

$prop1$ = 2

when Property prop1 contains the name of the property we want to compare
to 2. So, for example, if “prop1” had as its value “strength”, then the
expression above would be true if the value of the “strength” property
was equal to 2.

This will work in Vassal version 3.1 and higher.

Cards and Decks

Why do my cards disappear in a deck?

Whenever I try to add one or more cards to the deck, both the card AND
the deck outline disappear, and there is no way to make them appear
again.

This is a very common problem that reoccurs again and again with masked
pieces, of which cards are one. The module designer forgets to provide a
backside image for the piece or card. For masked pieces, you must edit
the piece and examine the masked trait. You must provide an image
for the reverse side of the card/piece. For cards, you would need an
image of the back side of the card (ideally, the same dimension as the
card face image), which you specify in the mask trait. You can also
specify how a facedown card appears to the player who owns the card.

If you omit the back image in mask, then when the card is flipped over
(as it happens when it goes to a deck), it disappears.

How do I send a card to the bottom of the deck?

The “Down Arrow” command sends a selected counter to the bottom of the
Stack, but if sent to card in a Deck, it will send it to the bottom of
the Deck. So, to send a card to the bottom of the deck use a trigger
that

issues the “Return To Deck” command
issues the “Down Arrow” command (Just press the down-arrow key in
the ‘Perform these keys’ section.)

Stacks

How do I show the number of items in a stack?

In the Mouse Over Stack viewer dialog box there is an check option for
Display Text.

Enable that and in the summary text select the sum(propertyname) option.

From the manual:
In addition to standard Properties, you can include a property with
the name sum(propertyName) where propertyName is a property defined on
a Game Piece. The numeric values of this property for all included
pieces will be substituted.

So give each piece a marker trait property with a value of 1 and a name
such as ArmyCount, then in the MOS viewer dialog, turn on the display
text with the field saying $sum(ArmyCount)$

Thanks to Timothy McCarron

Is there a setting to make a piece always be at the top or bottom of any stack?

There are two ways to approach this.

Does Not Stack trait.
You can use the ‘Does Not Stack’ trait with the ‘Never’ option to
force a particular piece to be always on the bottom of any stack and
not selectable. Good for terrain type pieces.
Game Piece Layers.
Add a ‘Game Piece Layers’ component to your Map to separate counters
into non-stacking layers.

How do I implement Un-moveable terrain pieces that I can interact with?

I’d like to create a game piece layer with a number of terrain-related
counters. I’d like to be able to right-click these counters to access
options to change their individual layers/appearance. However, I would
like to make it impossible for players to accidentally move these
counters and for the drag-select feature to ignore them.

There are a couple of options.

If you want the players to be able to manipulate the pieces, but not
easily or by accident, give the terrain pieces the ‘Does Not Stack’
trait.
If you want to make it so that players cannot manipulate the pieces
at all during play, then you can do the following:
1. Create your terrain overlays (or whatever they are) as actual
  basic piece counters. Then add the restricted access trait to
  the counter - assign the side to a fake player no one will use
  (i.e moderator). Place the piece on the board with an “at start
  stack trait”
2. All other traits such as sub menus, layers can be placed in the
  counter below the restricted access trait in the stack and still
  function normally for any player, except now they cannot move
  the piece (unless of course they join the game as the fake
  player:)

Counter and Game Piece Questions (Misc.)

What’s so good about prototypes anyway?

If you design your module carefully from the start to use Prototypes, I
guarantee you will save yourself much heartache and MANY, MANY hours
during on-going development and maintenance.

Do not even consider starting a new module without using prototypes. I
just can’t stress this strongly enough!

A prototype is just a set of gamepiece traits that can be shared between
the counters you define in your gamepiece palletes. As a general rule,
if I have any trait that is common between more than 1 unit, I put it in
a prototype and add the prototype to the units instead.

Say every counter in your module uses the ‘Delete’ trait. Just create a
‘Game Piece Prototype Definition’ called, say, ‘BasicUnit’. Add the
Delete trait to ‘BasicUnit’. Now when you create each unit, add the
Prototype trait ‘BasicUnit’ to each unit. Now, when each unit is
created, it will get the Delete trait defined in the prototype.

If you suddenly decide that every unit needs the Control key for Delete
changed from ‘Ctrl D’ to ‘Ctrl X’, you just change it in the ‘BasicUnit’
prototype.

If you then decide that every unit also needs the ability to have the
players add a label, then just add a ‘Text Label’ trait to ‘BasicUnit’
and voila, every unit will have text labels.

Prototypes can contain prototypes and Units can contain multiple
prototypes, so it allows you to create a hierachy of levels that contain
the behaviours of your counters. E.g., you might have prototypes for
‘Allied’, ‘Axis’, ‘BasicUnit’, ‘Infantry’, ‘Artillery’, ‘Vehicle’ and
perhaps 2nd level prototypes

e.g. 'AlliedInfantry' = 'Allied' + 'Infantry + 'BasicUnit'

When using prototypes in prototypes make sure that the order of
prototype definitions follows the same rule as the ordering of traits,
e.g. if prototype B uses prototype A, then prototype B must be above
prototype A in the list of prototype definitions.

e.g. AlliedInfantry would be above Allied; Allied would be above
Infantry and Infantry would be above BasicUnit.

IMPORTANT - Once a unit has been created and is on a Map, the prototypes
that created it no longer have any effect. You cannot change the
properties of units on a Map by changing prototype definitions. These
only affect units yet to be created!

How do I set the state of counters in the GamePiece Palette that use prototypes?

If you want your pieces in the palette to start in a certain state, then
in general, you can use key commands to put them in that state while
you’re editing the module and save. However, if the pieces use
prototypes, then the palette always loads with the default state of the
prototype. To solve this, you can change the state of a trait within the
prototype itself, rather than within each piece that uses it. In the
properties of the Prototype, just right-click in the area immediately
below the name of the prototype (where the view of the generated counter
is displayed) to modify that traits in thePrototype.
Here’s the annoying part. If the prototype doesn’t use any images, the
space where you need to right-click has zero height. Try resizing the
window to make it taller and it should appear as a white background.

How do I have Movement Trails turned on permanently?

Marking a unit ‘Not moved’ does not actually turn Movement trail display
off, it actually sets the visibility of the trail to the start setting
for the unit. This is controlled in the Movement Trail trait, by
selecting ‘Trails start visible’. These units will now start with the
movement trail visible and marking them as Not Moved will actually turn
trail display on! If you want to turn trail display permanently on, then
just select ‘Trails start visible’ for each unit and removed the Control
key. Marking a unit as moved still clears the current trail, but display
is left on.

Why does it take an extra step to rotate through game piece layers?

When you create additional Game Piece Layers, you are just creating
additional Layers under the default ‘top’ layer. So if you create 2
layers A & B, you now have 3 layers in total :- A, B and default.

Rotating the Layers rotates through all 3 layers, even if there are no
pieces on a given layer.

There is already an RFE in to add an option to the game piece layer
controls to ‘Skip empty layers’. This has not been done yet.

Thanks to Brent Easton

How do I delete a counter that does not have the Delete trait?

Save and close your game
Create a new Map called ‘Trash’ in your module and give it a blank
board.
Load your game back up, open up the ‘Trash’ board and move the units
you want to get rid of into it.
Go back to your Edit Module window and delete the ‘Trash’ Map
Save your game.

Here’s another method:

Create a new version of the module and give the pieces you want to
delete a Delete trait.
Use the Saved Game Updater feature to update the saved game
containing the pieces you want to delete. This will give those
pieces a Delete trait.
Load the updated saved game and delete the pieces.
Reverse the process if there are now pieces that should not have a
delete trait.

How do I replace a single card or counter with multiple counters?

The “Replace by Other” trait works when you want to replace a single
counter by one other counter. If you need to place multiple counters,
you need to use multiple “Place Marker” traits.

Build a trigger to execute the place marker traits and then use a second
trigger to delete the original card or counter, or return it to a deck,
etc:

CTRL P (Place all the markers)
CTRL ? (Remove/delete/Return To Deck Card).

Thanks to Tim McCarron

I have an old module with Clone and Delete Traits built-in, how do I get rid of them?

Current method to add Delete and Clone functionality is to add a Delete
or Clone trait to the counter, best via a prototype.

Old method was to put the Delete and Clone function keys directly into
the Basic Piece trait. If you create a new counter now, there is no
option to put Delete/Clone into Basicpiece anymore. But compatibility
means that of the module was created with an old version of VASSAL and
Delete/Clone where included in BasicPiece, then these will still appear
and be active.

To remove the Delete/Clone option from the Basic Piece trait, just open
up the Basic Piece trait and backspace over the the Control characters
in the ‘To Clone’ and ‘To Delete’ fields so the fields are left blank,
then save the trait. When you open the trait again, you will find the
whole Delete or Clone option is now gone. Then you can add Delete and/or
Clone trait’s to only those counters that need them (i.e. usually just
info markers).

How do I have Text labels with a Transparent background?

By clearing the current setting of the Background Color.

In the Text label trait, click on the Background Color ‘Select Button’.
Then click on the ‘Cancel’ button immediately. This will close the color
selector and set the Background Color swatch to white. Transparent
background color is now selected.

How can I have multiple colors, fonts, styles and line breaks in Text Labels?

Text labels are implemented using Java JLabels, so they support HTML.
Not exactly the most user friendly, but it works and would be useful for
setting up labels that do no need to be changed often.

 <html>Some <i>italic</i> and <font color=#ff4444>red <u>underlined</u> text</font>

Some italic and red underlined
text

Unfortunately, Bold does not work for the default Dialog font at
size 10, but you can just bump the size up or do stuff like:

 <html>Some <i>italic</i> and <font face="Arial" size=3 color=#ff4444>red <u>underlined</u> <b>bold</b> text</font>

Some italic and red
underlined bold text

How can you hide just a portion of a counter?

Use a mask and have it cover only the part of the image you are
concerned about and inaccessible to other player unless you turn off the
mask (restrict the mask command to the owning player or side).

Thanks to Tim M

Graphics and Images

Which image format is best for my maps and counters, JPG, GIF or PNG?

PNG format is recommended. See why.

I load images from different directories, but they are overwriting each other in the module?

In VASSAL, all images will end up in a single folder in the zip file
called ‘images’, regardless of where you load them from. If you have
used the same names for different images, then the images loaded later
would have overwritten the earlier images inside the module. You must
ensure that different images have different names in VASSAL.

How do I get really small writing on my counters that looks good?

You can get text as small as depicted on
the Sherman by hand drawing it, or by using a font which is legible at
very small point sizes (5pt or 6pt).

The example uses a font named “Small Fonts” which was distributed with
Windows 98. The free, open-source artwiz
fonts are an excellent source
of fonts legible at tiny sizes. When using fonts at very small sizes, be
sure to turn off antialiasing in your drawing program, as this will only
make them blurry.

Are there any free Graphics programs available?

VASSAL users have found the following free programs useful:

The GIMP
A full featured image manipulation program similar to Photoshop.

Inkscape
An vector image manipulation program, supporting the SVG format.

ImageMagick
A suite of extremely powerful command-line programs that can do just
about anything to an image that Photoshop et al. can, plus many things
that they can’t. Great for applying transformations to many images in
batches.

SplitImage
A useful utility for splitting counter sheets up into individual images.
Windows only.
CAVEAT: SplitImage has a bug that creates corrupted PNG images that
cannot be directly loaded into VASSAL. You must load and save any image
with another graphics program (e.g., GIMP or ImageMagick) to fix the
image before loading into VASSAL.

OptiPNG
A small utility to make PNG files smaller. Also converts other bitmap
formats to PNG.

How do I extract an image from a Powerpoint Presentation?

To save a whole slide: Open the powerpoint presentation and go the slide
you want. Select ‘File’ -> ‘Save As’ and the change the ‘Save as
type’ from ‘Presentation (*.ppt)’ to ‘(*.gif)’ or (*.png) and save.

To save an individual slide element: Select the image or background to
save and right click, select ‘Save as Picture’ and save it as a GIF or a
PNG.

How do I delete an unused image file from my module?

To remove an unused image file, you will have to manually edit the
module file. Module files are zip archives, so you will need to use a
zip archive tool:

Unzip the module into an empty directory
Locate the unused image file in the images folder and delete it
Zip the contents back into a single module file

Some common zip archive tools are Winzip or 7Zip for Windows, and the
command line zip program on Mac and Linux. To work with the tools, you
may also need to change the filename to end in .zip instead of the
normal .vmod file type. Remember to rename it back afterwards.

For newer versions of Vassal, just use the “Tools->Remove Unused
Images” tool in the Module Menu bar.

Reports

How do I get the Player Names to display in my movement reports?

In Global Options, make sure you have the ‘Player Id Format’ set up with
at least ‘$playerName$’. If you are using Sides, then something like
‘<$playerName$[$playerSide$]>’ is good too.

Then, in the ‘Auto Report Format’ boxed in your Map Window definition,
include $playerId$ in the reports.

$playerId$ $pieceName$ moves $previousLocation$ -> $location$

You can also use $playerName$ and $playerSide$ directly, but the global
Options let’s you set up $playerId$ as a shortcut for a more complex id
tag that can be used anywhere.

You probably also want to include $playerId$ in any ‘Report Action’
traits also.

How can I restrict Auto Report of Movement to specific pieces?

Turn the map based auto-reporting off by setting the ‘move’ report
format to blank.
Add a Key Command(Say Ctrl-A) in the ‘Key Command to apply to all
units ending movement on this map’ field.
Add ‘Report Formats’ reporting on Ctrl-A to the units you want to
report movement.

Thanks to Brent Easton

I have a Report Action that refuses to work!

In the Map configuration, check the field ‘Auto-report format for units
modified on this map’. This should be something like ‘<$playerId$>
$message$’. This field controls the overall format of ‘Report Action’
reports for this map.The $messsage$ is replaced by the text generated by
‘Report Action’ trait. If this field is blank, ‘Report Action’ traits
will never report anything on this map.

If you’re giving the command while the piece is still in the palette,
some of the text (having to do with location) may not appear because the
piece isn’t on a map. Otherwise, of course, you must drag a new copy of
the piece to the map after making the change to the Report Action trait.

Oops

What can I do about OutOfMemory errors?

Color depth is the main culprit eating up memory in VASSAL. It doesn’t
matter what the image compression level is. You don’t get savings unless
you use a reduced color palette. Using the same palette for all your
images will help as well. You can also get a benefit from reducing the
number of colors used in your Display settings. For some reason a large
image takes up more space than several smaller images, so you can break
up large map images into smaller pieces. You can reassemble them as
Boards using the default Board layout, so players need never know that
the map’s been broken up.

Why is the New Game Wizard Window so Big?

The size of the new game wizard window is determined by the size of the
options in the drop-down menus and by the size of the splash screen. Use
of an excessively large splash screen image can lead to a window that
will not fit on all user’s displays.

Developers: Please use a fairly small splash screen for your module.
Also make sure that the names of sides and boards are not too long.

Users: If you find a module with a startup wizard screen that is too
large, you can fix this by modifying the module. Unfortunately, you
can’t do this from the editor directly. You will have to open the module
using a tool that can unzip the file and then delete the “Splash.gif”,
“Splash.png” or “Splash.jpeg” file from the Images subfolder. Then zip
the file up again.

When I try to Import a Custom Class, nothing happens!

If the custom class generates an exception while being loaded, it will
fail quietly and generate an error message in the Errorlog file.
Check the following first:

You are using the correct spelling for the custom class (watch
upper/lower case).
You are using ‘.’ to separate components in the name, not ‘/’ (i.e.
‘Test.myComponent’ not ‘Test/myComponent’).
Make sure you have loaded the class files into your module zip file.

If the component still fails to load, then send a copy of your Errorlog
file to the component developer.

How do I get the default Quick Start/User Guide/Splash screen back?

If you accidentally edit or delete the entries for the default Quick
Start guide, VASSAL User Guide and the standard Splash Screen, you can
lose the original settings and it is not possible to restore them
through the module editor. To fix these, you will need to Edit your
buildfile, find the appropriate lines and replace them with the default
values:

<VASSAL.build.module.documentation.AboutScreen
fileName=“/images/Splash.gif” title=“About VASSAL”/>

<VASSAL.build.module.documentation.HelpFile
fileName=“/help/Intro.html” fileType=“resource” title=“Quick Start”/>

<VASSAL.build.module.documentation.HelpFile
fileName=“docs/UsersGuide/index.htm” fileType=“file” title=“User’s
Guide”/>

Other

How are Player Hands and Private Windows different?

Player hands are private windows with the addition that pieces are
spread out like a hand of cards instead of a stack of counters.

How do I create a player who can observe all the private windows?

How do I create a player who can observe all the private windows (each
player will have the cards in his window) and protect that “master”
player with a password? And to protect each window with a password?

You can create the “master” player in the Definition of Player Sides,
then list the master player as one of the owners of the private windows.
When starting a new game, the first player to select the “master” side
will be the master for the rest of the game, tied to his password in the
preferences. If you never want anybody other than yourself to take the
master side, create a Pre-Defined Setup from a saved game in which you
have taken the master side. Then put the Pre-Defined Setup into the File
menu in place of the normal New Game entry. The master side will be tied
to the password you had when editing the file.

Can you have Pre-Defined setups and still have “New game” in the File menu?

Yes. It’s an option in the Pre-Defined Setup properties. If you don’t
specify a saved game, it starts a new one like the normal ‘New Game’
command. Check the Reference Manual.

I have a great idea for an enhancement, but am not a programmer, what do I do?

Discuss the idea on the Forums and
get other peoples ideas. Generate some energy. Work out as much detail
as possible:- What buttons, windows, controls are needed? How do they
interact with each other?

When you have a good feel for the structure of your enhancement, go to
the Vassal page at the Sourceforge
site and create a new
Request For Enhancement (RFE) with your idea. Include as much detail as
you can. Try and have a good idea of what the enhancement will look
like, what commands/buttons/windows etc. it will need. This does not
mean that your idea will get done, but it creates a central reference
point for information and comments on your idea.

Two of the biggest time burners for developers are Analysis (Working
out the details of what it needs to look like and it how it works from a
high-level point of view) and Testing. Neither Analysis or Testing
required programming experience and if you can make yourself available
for these, you have a far better chance of getting a developer
interested in your project.

How do I make my Module smaller?

Everything you ever wanted to know about trimming the fat from your
modules’ bulging waistline.

What is the buildfile and how do I edit it?

The buildfile is a text file that describes the components of your
module and how they fit together. A module file is just a zip archive,
regardless of what it is called. You can open the module file using any
standard tools for manipulating Zip atchives. If you are having trouble,
try changing the name of the module file to .zip. You will
find the buildfile inside the module archive at the top level. Extract
it out and edit it with any standard text editor. After making changes,
make sure you save it back as a text file. Then, copy the buildfile
back into your module Zip archive and rename it back to its original
name.

Here’s an example of how to change all occurences of ‘Activate Ctrl A’
to ‘Mode Change Ctrl Z’:

//You can edit the buildfile if you are very, very VERY careful and take
a backup before you start.

Inside your module, you will find a file called buildfile. It is a text
file that describes the contents of your module.

Take a copy of this file and have a look at it, you will see the entire
setup for your module.

Now, edit your module, choose two similiar counters and make the changes
you want to make to one of them. Save the module. Copy the buildfile,
edit it and find where these counters are defined. Look carefully at
what has been changed from the unchanged unit to the changed unit.

It will be something like changing ‘Activate;2;A’ to ‘Mode Change;2;Z’
for the activate fix. Make sure you don’t remove any of the ‘;’
characters.

Use Edit/Replace in your editor to CAREFULLY make the same changes to
all units.

Take a copy of your module.

Finally copy the modified buildfile back into your module and test.