A piece of advice
You can use your own levels whith Liquid War 5. The only thing you have to do is to put your own 256-colors vbitmap files in a special directory, and the program will use them. Currently, BMP, LBM, PCX, and TGA files are supported. It is a good thing to use 256 colors bitmaps, for they waste less disk space than truecolor bitmaps, and Liquid War 5 converts all bitmaps to 32 colors bitmaps. Additionnally, truecolor bitmaps might cause the DOS version to crash randomly... 2-color bitmaps will also cause the program to crash. I warned you!
The best thing you can do to create your user levels is to have a look at the few user files I put in the .zip file and try at first to do something that looks about the same!
Liquid War 5 does many checks on user levels and is much safer than Liquid War 3. Still, try and help the program not to crash, if possible.
Liquid War considers that dark colors are walls and bright colors are associated to the playable area. So you can draw your walls in black, dark blue, etc... And the rest of the map can be of any bright color such as white or yellow.
You can draw a small map on a big bitmap, as long as you use a bright background color. Liquid War will autodetect the range of your map and add the border line if necessary.
Liquid War re-orders all the maps, so that the smallest ones are on the left and the most complicated ones on the right when you choose them with the slider in the "map" menu. So if you can't find the map you just draw, don't worry, it is probably just mixed with the levels from the .dat file.
The default path for maps is "custom\map\" on windows, and "/usr/local/share/games/liquidwar/map" on GNU/Linux.
All you have to do is put a bitmap in the default directory which is "custom\texture\" on windows, and "/usr/local/share/games/liquidwar/texture" on GNU/Linux.
As of Liquid War 5.6.x, it's possible to associate a map with a texture. All you need is to call the maps with the same name (case is important, lowercase recommendend...). Look at the "meditate" custom map which is shipped with Liquid War for instance.
This also works with internal builtin maps (those stored in the datafile) so for instance if you name a custom texture "world1.bmp" it will automatically be associated to the builtin map world1 (to figure out internal names you have to unpack the source distribution and look in the ./data directory). This also works the other way, if you name a map "wood2.bmp" it will be automatically associated with the builtin texture wood2.
Associating a texture with a map requires more work than designing a simple map, but the results is usually much nicer. See the "Kasper - ..." series of maps for instance.
Send your levels
Maybe you will find that the original levels are ugly and unplayable. Well, if you have made user levels and think they are great, just send them to the Liquid War user mailing list. Please use only 256 colors bitmap and zip them before sending them, or else they might be blocked by my provider...
As of today, dozens of user maps have already been included in Liquid War, this is very nice for it happens that every map designer has his own personnal tastes, so the maps all look different.
Still, to be included in Liquid War's mainstream distribution, your maps will need to be placed under the terms of the GNU General Public License, or at least a compatible license. You should have received a copy of this license with Liquid War anyway. Read it 8-)
Of course, you can use *any* map when playing. You can even play with a bitmap you got from a proprietary source - such a proprietary game you bought for instance - but the point is that I can't - and you can't either - distribute such a map along with Liquid War.
However, this is enough legal boring stuff! What you should keep in mind is that I'm always happy when I receive maps from players, and it's a pleasure for me to include them in the mainstream distribution.