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Sunday 20 July 2003

How do I create my own Co-Op mods for MoH:AA

If you have read my earlier post you may be interesting in creating levels for Medal of Honor: Allied Assault, that can be played cooperatively with others.

To do this you will need to find out as much as you can about scripting. I have listed a few notes to help, but, unfortunately, I don't have the time to make these pages complete. There are much better web sites for that. See the list at the end of this page. I have just tried to add a few notes, that are missing or incomplete on other sites.

What do I need installed?

Download any of my coop maps.  Here is a good one to try: (3.1MB)

Within all of the coop level downloads you will find the following files which you will need for your own levels: - Required files to be able to play a Co-Op level Including
x_jcbmain200.pk3 - installed in the main folder
x_jcbmainta200.pk3 - installed in the mainta folder

These include changes to the sound file and the generic human to work with Co-op and other modded levels. Also included is the Select Mission option in the briefing room.

x_jcbextras508.pk3 - Some additional scripts I have used in this modification
x_jcbchanges100.pk3 - reduction of the melee damage, this affects all games not just coop!

Except where stated, the files MUST be in the ...\MOHAA\main folder.

Extract the contents of the PK3 files, using Pakscape, and read the comments in the script files.

What do I need to know to start Modding MOH:AA

See any one of the other Mod sites listed at the end, plus read a few of my notes:
How to get MOH:AA Co-Op to work - Set of notes to help create Co-op games from Single Player maps
MOH:AA Scripting - Notes I made for myself to help me create the scripts
MOH:AA Commands and Variables (150Kb) - Word document which I've compiled for my own reference while working on the above mods

Where else can I find out about Co-Op modding

Co-Op Big 5 Map Pack 1 home page - Collection of Co-Op missions including generic fix for co-op sound
Omaha Co-Op map - Useful example of Co-Op mods
Pakscape - Good tools for extracting files from .pk3 archives.
Extract the zip file and make sure any .pk3 files are in the '.../MOHAA/main/' folder. MOHAA will then automatically register the maps or other mods.

Forums and Information

Official MOH:AA site - links to more links
The Modding Theatre - helpful forums and links to more MOH sites
MOH Match - Good for a few downloads
LOKI's Modding Theatre - Some tutorial for Modding MOH
Nemesis's Tutorial Page - Very clear MOHRadiant mapping tutorials and some scripting
The Rjukan project - Very professional modding project
.map MOH:AA mapping project - Another usefull modding site

Saturday 5 July 2003

Coop Mode for Medal of Honor: Allied Assault

Medal of Honor: Allied Assault does not have a Co-op mode as standard.

With a bit a messing about it is possible to play some levels cooperatively.

What is Co-Op play?

This is where you and your friends combine forces to complete the missions within the game. You all compete against the computer.
The maps and levels have to be created or modified to be played co-op. It is not perfect because the game does not have special features for playing Cooperatively, it's just a lucky coincidence available in the game.

What do I need?

You need someone to play on a machine running the server and everyone else play as clients.
You will have to be running, at least version 1.11 of the game and you will need the modified files, required to play the game, installed on both the server and all the clients machines.

Before any of the levels will work, you will need the various fixes and add-ons. Make sure the folowing are installed:

Download any of my coop maps.  Here is a good one to try: (3.1MB)

The numeric digits may be a higher numbers, they are the version of the file and ensure that future versions will work, even if the olf version is still installed.

How do I install the files?

All MOHAA mods are installed the same way, simply copy the files ending '.pk3' in to the 'main' folder with all the other '.pk3' files.
The default location for MOHAA to install is,

C:\Program Files\EA GAMES\MOHAA\main

The mods are distributed in compressed zip files, to keep bits together. Unzip the file, using your favourite zip extractor, or Windows XP built in compressed folder view.

Each modified level is supplied the same way, and needs to be uncompressed and the '.pk3' file copied in to the same place.

What do I do now it's installed?

Run MOHAA as normal, and set yourself up, with a name and character model.

Once that is complete, if you are the server, you need to exit MOHAA. If you are the client, go to the briefing room...

I want to run the server, what do I do?

Various options must be set to run the server. To do this, use the shortcut provided.

The shortcut, sets all the server settings and runs the level. You will eventually see the Server connection menu.

Use the information on this screen to help the client players connect.

Wait for all the players to connect, then press the 'Continue' button.

I am going to be one of the clients, what do I do?

Mainly, wait for the server!
Go to the briefing room, to select a mission:

If you have the mod installed correctly, you will have an addition option on this screen, the 'Select Mission' page.

Click on this to bring up a list of all the levels installed.

When playing Co-Op it is essential that the server and the client select the same map. Find out from the person running the server, which map to run. Double click on that map name.

Wait for the map to load.

When the level has loaded a connection menu will appear.

Find out from the person running the server, their IP Address and Port number. Enter those details in the space provided, in the following format:

Press the connect button.
Wait for the map to connect, this may take a few minutes. Don't worry if the screen is grey to start with, move about a bit and it will redraw correctly.

Wait for all the players to connect BEFORE you shoot anything. If there is any action the server gets too busy and the other clients can not connect.

When everyone is ready, go shoot things...


I have more questions?

The above is all you need to run the game, but If you want to know a little more, read on.

How powerfull does my computer need to be?

If you are playing on a client, any computer able to run MOHAA in single player mode, is fine for Co-Op.
If you are running the server, you will need a more powerfull computer. This is because every enemy in the level has to be controlled, in addition to keeping the whole thing together!

I have run the server on a machine as low as an 800MHz Intel Pentium with 384Meg RAM. This was slow and unresponsive and is not recommended. A 1GHz AMD Athlon with 512Meg RAM, was fine, a 1.8GHZ Pentium with 512Meg RAM was good. I currently run it on a 2.5GHz Pentium, with 1Gig RAM. This is overkill :-)

Co-Op can not be run on a dedicated server.

What do the files do?



This adds the briefing room menu, that lets you select any map to play. It also changes a couple of fundamental models that allow the characters to work in Co-Op mode. (It does not interfere with normal game play.)


These are global scripts used within the levels. Among other things it contains the co-op menus, the scripts to spawn troops and weapons, plus the teleport system to avoid players spawning on top of each other. This file is essential for any of the levels to run. (It does not interfere with normal game play.)


This file reduces the damage done by melee. That's hand to hand, or tooth to groin, combat. I strongly recommend it for Co-Op play because it lets you survive a dog attack and the attack from the butt of the enemy weapon at close range. Unfortunately it affects the single player game, where it tends to make the dogs harmless! You may want to remove this file, before going back to play the single player game.

What is the Teleport System?

I originally created this as a way of minimising the chances of players starting on top of each other. This is caused because the mods are based on the single player levels which only have one start point. I developed this further so that you can move the start points. This makes Co-Op games much more fun, when you die, you start much nearer the action and don't have to spend ages running half way across the level.

I have older co-op levels, are they compatible?

No. The new levels use new menus, and different scripts to run. If the co-op levels were produced by me, I have converted them all to the new versions. See my web site.

Does this work with other Mods?

If two mods change the same file, one of them will not work. It is imposible to make all mods compatible, if in doubt or something does not appear to work, remove all other mods.
The '.pk3' files used by the game and mods are loaded in alphanumeric order. The highest letter wins.

I can't upgrade to game version 1.11, what do I do?

I have only been able to get Co-Op play to work properly, if I patch up to version 1.11 of the game. If you stick to an older version, you're on your own.
If you can't upgrade your game because it claims you have the wrong country version, there is a registry fix to correct the version number, and then the upgrade will install.



I'd like to thank the numerous people on Forums, Newsgroups and Web Pages who have provided useful information to help me write mods and prepare these notes. Most of you are unidentifiable or lost in the mists of re-posts and quotes. If you happen to see something that you think you originated, then you are probably correct, and many thanks.