Installation Guide:

1. Prep work.

1a. Set some vars we’ll need later to avoid typos

$ BTA_SOURCE="$HOME/src/BATTLETECH/BTA"
$ BT_ROOT="$HOME/.steam/debian-installation/steamapps/common/BATTLETECH"

1b. Ensure dependencies are installed

Package managers vary from distro to distro, so it’s assumed you know how to navigate the distro you’re using.

I’m using Pop_OS!, which is of Debian lineage, so that’s what this how-to will use.

$ sudo apt install wine unzip jq

wine -- to run the installer
unzip -- to unzip the mod package
jq -- to allow the pathfinder.sh mod path fixer to parse mod JSON files

1c. Prepare a Wine prefix for the BTA installer.

$ mkdir -p "${BTA_SOURCE}"
$ cd "${BTA_SOURCE}"
$ wget https://dl.winehq.org/wine/wine-mono/6.1.0/wine-mono-6.1.0-x86.msi
$ WINEPREFIX="${BTA_SOURCE}/wine64" WINEARCH=win64 wine msiexec /i wine-mono-6.1.0-x86.msi

1d. Download the BTA Installer and Extract the .zip into ${BTA_SOURCE}

You’ll have to manually download the installer from NexusMods; then:

$ unzip "BattleTech Advanced 3062 Installer-452-v8-5-2-1613256258.zip"

1e. Prepare the Mods directory

If you try to run BTA alongside other mods, you are likely to have a bad time.

If the Mods directory already exists, delete it. Then (re)create it.

$ rm -rf "${BT_ROOT}/Mods"
$ mkdir -p "${BT_ROOT}/Mods"

2. Run the installer

$ WINEPREFIX=$HOME/src/BATTLETECH/BTA/wine64 WINEARCH=win64 wine BTAdvancedLauncher.exe

3. Configure the installer

3a. Click the "Advanced Mode" button.

3b. Collect the installer paths

The installer needs to know where to install to. It cannot seem to browse into "hidden" paths (such as $HOME/.steam). Instead, you must copy and paste paths into the installer’s file/directory chooser after clicking the "Browse" button.

To add further complication, the installer seems unable to parse forward-slash-delimited paths. You must convert to back-slash-delimited paths. You also must include the Windows drive letter "Z:".

And so, let’s

3c. Get those Windows paths:

Install Target path

$ echo "Z:${BT_ROOT}/Mods" | sed -e 's#/#\\#g'

The output should look like:

Z:\home\indigo\.steam\debian-installation\steamapps\common\BATTLETECH\Mods

Checkout Workspace path

$ echo "Z:${BTA_SOURCE}" | sed -e 's#/#\\#g'

BattleTech.exe Binary path

$ echo "Z:${BT_ROOT}/BattleTech" | sed -e 's#/#\\#g'

3e. Input the Install Target path

Click the "Browse" button next to Install Target and copypasta the output into the "Filename" field of the file picker.

3f. Input the Checkout Workspace path

Click on the "Browse" button next to Checkout Workspace and do like you did in 3e.

4. Install BTA

Click the "Install and Update BTA" button. Pay attention to any popups or instructions.

4a. Wait for it.

At some point the installer will complain that it cannot find BattleTech.exe and ask you for help. Remember that "BattleTech.exe Binary path" we generated earlier? Give it that.

5. Ensure all the paths and symlinks are correct

At this point the installation for Windows is complete. However, HBS was kind enough to provide us with a native binary, so we have to change the Windows mod paths to POSIX VFS semantics.

Thankfully some magical creature named "b2cc" has already written a script to do this for us. The script is called "pathfinder.sh". Let’s download an run pathfinder.sh now.

$ cd $HOME/.steam/debian-installation/steamapps/common/BATTLETECH
$ wget https://gist.githubusercontent.com/b2cc/c312bec251aaecbfedd07e4d4bda512e/raw/f7fdaa5bc458372b421a6a207e93c4d9ea257901/pathfinder.sh
$ bash pathfinder.sh -c

You should see a lot of console spam and green happy words.

6. Okay, that’s it.

All done. Go stomp. Get your dakka dakka pew pew on.

Troubleshooting

The game loads but the main menu doesn’t say "BattleTech ADVANCED - 3062" and the ModTek version doesn’t show up under the game version next to the CREDITs button.

Cause #1: ModTek isn’t patched into the game correctly.

This can happen if mono is incorrectly installed or was not installed before the BTA installer was run the first time.

Solution: (re)run the ModTek Injector. It should look like this if it worked correctly:

$ cd $HOME/.steam/debian-installation/steamapps/common/BATTLETECH/Mods/ModTek
$ WINEPREFIX=$HOME/src/BATTLETECH/BTA/wine64 WINEARCH=win64 wine ModTekInjector.exe 
ModTek Injector
---------------

Assembly-CSharp.dll backed up to Assembly-CSharp.dll.orig
Injecting Assembly-CSharp.dll with ModTek.Injection.LoadModTek at BattleTech.Main.Start
Writing back to Assembly-CSharp.dll...
Injection complete!

If you have any issues, feel free to ping me on Discord.