Level editor for Lemmings.

Originally released at Lemmings Forums

SMS Lemmings Level Converter

In order to use this tool properly, you need:

Designing levels using Mappy

First, you need to make a map. Open MappyWin32, and make a new map. Feed it the following information:

After clicking OK, you now need a tileset to load. The tilesets should be included with the zip file you downloaded. Note the number before the filename. This is the tileset ID that you need to provide later on.

To load the tileset, click File -> Import, then find and load the PNG file of the tileset you want to use.

Now, make your map. A few things to bear in mind:

When you’ve finished making the map, I recommend you save it first for backup purposes.

Now you need to export the map to a file format the tool can read. There are two methods available.

To prepare them for use in Mappy, copy the scripts to the luascr folder where you installed Mappy, then open MAPWIN.INI (or copy the included MAPWIN.INI and overwrite the original). Scroll down to the lua scripts section. Add a new line.

lua16=Export Lemmings level.lua

If you want to be able to import MLM map files, you need to replace one of the other Lua scripts with "Import Lemmings level.lua" (without quotation marks). This step is optional.

Mappy is now set up to save files as MLM files. To save the file as a MLM file, go to Custom -> Export Lemmings level, then give it a file name. To load MLM files, make a map with an 8x8 tile size, and import the tileset the level uses. Then go to Custom -> Import Lemmings level, and choose the file you wish to load.

*.MAP CDXMap files: The level converter can also use CDXMap files. Go to Custom -> Export binary file. Give it a file name, and adjust exported values by 0.


Now you need to edit this file to provide the converting tool with the level details. When you have finished, save it whilst keeping the original file name.

The settings are written within angle brackets < and >. This is followed by a space, and then the value. Text-based values (which are <ROM Load>, <ROM Save>, <Map File> and <Name>) are enclosed by quotation marks "".

The settings available are as follows:

<ROM Load> ""
<ROM Save> ""
<Map File> ""
<Name> ""
<To be saved> 
<Release rate> 
<Fall Distance> 
<Trap Type>
<Trap X>
<Trap Y>
<ROM Load>
This is the original ROM file you wish to edit. Copy the file name, paste it here, and remember to put quotation marks around it.
<ROM Save>
This is the name of the ROM file you wish to create. I recommend you give it a different file name from the <ROM Load> setting. Don't forget to add the .sms extension at the end of the filename.
<Map File>
This is the map file you wish to implement into the ROM. .mlm files are supported, as well as .map files exported using MappyWin32.
You may set this value between 1-30.
This is the rating you wish to insert the level into. <Rating> is a numerical value, where:
This is the ID of the tileset your level uses. The tile ID is the number before the the tileset's filename.
This is the name of the level as it appears ingame.
The number of lemmings the level uses is currently being restricted. Only 1, 2, 4, 5, 10 and 20 lemmings are supported, due to the way the game calculates percentages.
<To be saved>
This value represents the PERCENTAGE of lemmings you need to rescue to pass the level.
The time available in minutes.
<Trap Type>
is the type of trap your level will use. If your level does not feature a trap, set this value to 0. If it does, then...
set this value to...if you're using...
1Bricks (tileset 4)
2Sand 2 (tileset 6)
3Grass (tileset 0)
4SEGA (tileset 7)
<Trap X> and <Trap Y>
is the X and Y location of the trap in the level. By default, it's the tile numbers across (Trap X) and down (Trap Y). If you wish to use a specific pixel within the level, the routine can be overwritten by prefixing the value with x (Trap X) and/or y (Trap Y).


If you're using the tile count, note the location of the highlighted trap tile when using Mappy. These are the co-ordinates you enter to place the trap there.

All other settings are self-explanatory, and may be set between 0-99, except <Fall distance> (maximum is 255).

Running the converter

Before running the converter, make sure the ROM you're loading, the map file you're using, and leveldata.txt are all in the same folder.

Now run the program. If everything has gone to plan, you will find a brand new Lemmings ROM sitting in the folder. If not, you'll be given an error message. Make sure the settings in leveldata.txt are accurate, the map format is correct, and double check that all files are in the same folder.

If you're still having problems, you know where to find me. ( My username is Pooty.







  1. ^ Tileset 5 was supposed to be the SEGA tileset originally, but it is broken ingame, and therefore unusable.


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