A massive demonic invasion has overwhelmed the Union Aerospace Corporation's Mars Research Facility, leaving only chaos and horror in its wake. As one of only a few survivors, you must fight your way to hell and back against a horde of evil monsters.
IMPORTANT NOTE: Read the description for instructions before installing.
Warning: This patch is for 2004 Edition game owners only, BFG Edition and Steam version owners do not install this patch.
Unlike 1.3.1, this patch doesn't require any previous patches to update your game to 1.3.1, it directly updates it to that version, it contains all files from patches released prior to the 1.3.1 patch to make sure you don't get errors after installing the patch, here's why you should install this before installing official patch:
This patch has been only tested with CD-Retail 2004 version of the game, so it will not work with BFG Edition, it should also work for every version of the game.
How to install the patch:
NOTE: do not install this on the Steam version, that version should be already updated to the latest version so you don't need to install this on it.
How to find out whether the patch worked or not: Start up the game and open the Console, It should tell you what game version are you running on bottom left of console.