Hi Ibn-Khaldun,
Unless both mods use their own mod folder, rather than overwriting files, one cannot usually use two modifications at once. Presumably XGM doesn't use this function, so more than likely cannot be played alongside EB.
To play both mods at once, you will first have to uninstall R:TW. It would be advisable for you to follow these instructions, since this will also clean up all XGM files in addition to vanilla files.
After you've done that, re-install the game and start a campaign. After the campaign has loaded up, close the game down, and patch up to v1.5 if required.
Before continuing with my steps, I must issue a word of warning - they work in theory, but may not work in practice. I don't have R:TW installed to test it, so I can't really investigate it for myself. Sorry.
Install XGM. When it asks you where you wish to install the mod point it into "[your R:TW directory]\xgm". The file path you need to insert will by default be either:
"C:\Program Files\The Creative Assembly\Rome - Total War\xgm"
should you have Gold, or:
"C:\Program Files\Activision\Rome - Total War\xgm"
should you have a standard version, not Gold.
Then create a new shortcut to access the XGM modification on your desktop. Right click, select "New" and then select "Shortcut".
When the wizard asks you for the location of the file, type in ""[your R:TW directory]\rtw.exe" -mod:xgm". Typically the file path will be by default either:
""C:\Program Files\The Creative Assembly\Rome - Total War\rtw.exe" -mod:xgm"
should you have Gold, or:
"C:\Program Files\Activision\Rome - Total War\rtw.exe" -mod:xgm"
should you have a standard version, not Gold.
Name the shortcut "Rome - Total War - XGM" and save it. Then load the game up through the shortcut, and ensure that XGM is running normally through it.
Next, download and install EB into your R:TW directory. The location you will need to insert when requested will by default be either:
"C:\Program Files\The Creative Assembly\Rome - Total War\"
should you have Gold, or:
"C:\Program Files\Activision\Rome - Total War\"
should you have a standard version, not Gold.
Then load up EB through the shortcut it installs, and see if it is working as normal. Do the same for the XGM shortcut you made earlier, and ensure that it is also working properly.
If everything is running fine, then congratulations! If not, then feel free to ask in the thread for further advice.
Hope this was of use to you, good luck!
Bookmarks