|Edited: 13/05/18 12:10
A fake patch (or false patch) describes one way of installing modifications (or mods) for use with the game. Instead of being installed in the mods folder of the game and selected from the splash screen, the data for the mod is installed directly in the main directory of the X-installation and works as a "patch" for the game.
This method works only with a mod which offers its data in files of .cat/.dat format. It is, though, also possible to install the folders of a mod directly into the game's main directory; however, maintenance is more difficult and it's more likely that these files will be mixed up.
It is also vital to take into account that official patches from Egosoft will overwrite any .cat/.dat in the main directory with the same name. Thus, you should also keep the files of the mod in a safe place outside of the game's main directory!
As said before, using a mod as a false patch involves installing the mod files directly into the main directory of the X-installation. You will need to rename both files, the .cat and the .dat, to use the next available number. For example, if you already have files 01.cat/.dat through 09.cat/.dat then the next available files are 10.cat and 10.dat.
If both the .cat and .dat files do not have the same number, or if they don't get the next free number, then the game will not recognise the false patch.
By using this method you can have as many mods installed as you want. However, you should take into account that different mods may alter the same data. If that is the case then you cannot use one of the mods. You could, though, ask the creator of the mod to change the file(s) to make it compatible (or try to change them yourself).
It is neither necessary nor possible to choose these mods from 'Select Mod Package' in the splash screen, and you cannot deactivate or delete them from your game in that way. Generally, it is almost impossible to play a modified game without the actual mod files available, because these are rooted to the save game and deleting the mod files from the directory will normally result in an incompatible save.
Modifications on the game as well as on modifications made by yourself always happen on your own risk and you cannot hold either Egosoft or the creator of the mod responsible for any damage or errors in your game which result from these modifications.
Note on using fake patches with X3: Terran Conflict and X3: Albion Prelude:
X3: Albion Prelude (X3AP) is an addon to X3: Terran Conflict. Although X3AP has its own installation folder ("addon") where it keeps its specific files within the X3TC directory - this means that scripts, mods within the mods folder and savegames are handled independently from X3TC - X3AP also uses files from the X3TC base installation. This means that mods installed as a fake patch for X3TC may have an impact on X3AP, too. Therefore it's a good idea to make sure that the X3TC installation X3AP is based on is clean from all modifications or at least does not contain any fake patch mods. If you want to modify both games, X3TC and X3AP, you should create multiple installations.