There is a wealth of ways to add to the content in X-Wing vs TIE Fighter, and its expansion, Balance of Power. But what many do not know is that there are already many missions in the game data of every copy of the game that are unplayable by normal means.
The mission data is divided into data for training exercises, melees and combat engagements, in the folders Train, Melee and Combat. The missions available in the basic game exist as .tie files. These files are referenced on a document called MISSION.LST (each folder has one of these), in the form
(number) mission_filename.tie Mission Name
That is, each mission is numbered individually, the next line lists the .tie file to be loaded when the mission is played, and the bottom line is the name of the mission as it appears in the menu in XvT - for example, the first Rebel training mission is listed as
0 1TA02BZ.tie Gunnery Training
When a player creates a mission using an editor, they need to add these three lines to the MISSION.LST file for mission to be playable. Where both the Rebels and the Empire have different missions (i.e. exercises and melees) there is also a REBEL.LST and IMPERIAL.LST file that must be edited in the same way as the MISSION.LST file.
However, if we look at the MISSION.LST files and compare them to the .tie files that come with the game, we'll notice that there are some .tie files that are not represented in the MISSION.LST files. These missions, for whatever reason, were not intended to be played by the game developers.
Let's add the secret Rebel training exercise first. This mission's filename is 2TA03BX.tie. It is a 2-player co-op mission. Open the TRAIN folder in your XvT directory, then open the files MISSION.LST and REBEL.LST.
There are a total of 85 training exercise missions (including the campaign missions from BoP), so we'll number this mission 86. If the number is the same as that of another mission, the game will consider the two missions the same and scores, awards, etc will be duplicated for both missions. Furthermore, all players in a multiplayer game need to have their missions listed the same as each other, so we'll make sure that we all have matching entries for the secret missions to ensure we can fly together.
On both REBEL.LST and MISSION.LST, the last entry for [Rebel Training - 2 Player Cooperative] is:
24 2XD01BX.tie Protect Escaping Rebel Frigate
On the next line for both .lst files, add:
86 2TA03BX.tie TIE Fighter Interdiction
After completion, when you next look at Rebel training exercises, this mission will be there for you to play! It's easy to see why it wasn't included in the final game as a playable mission. Although it's enjoyable, it doesn't offer a lot of variety, or train the pilot on any skills that can't be learned in other exercises. However, it is a fun mission and a challenge, and actually plays very similarly to many of the missions in the original X-Wing game.
Now we'll add the hidden melee mission:
Open the Melee folder in your XvT directory, and open MISSION.LST. The filename of the secret mission is 8MD2AW12.tie. There are 32 other melee missions if we include those on BoP. As this mission is testing a particular skill, warhead interception, we'll place it under the [Special Skills] heading. So our entry (last one on the file, below 'Escort Duty for Two-Man Teams')is:
33 8MD2AW12.tie Anti-Warhead Defense for Two-Man Teams
Add this text and the mission will be playable:
Note that to play these missions in the Balance of Power expansion, you will need to look in the Balance of Power folder in your XvT directory, and update the .lst files in BoP's own Train, Melee and Combat folders.
While you're doing that, pay close attention to the contents of BoP's Melee mission.lst file. Notice that there are a lot of missions that aren't in the exact format we've been entering? Instead, they look like this:
13 & 8MF1WF.tie TIE Fighter Challenge
These missions are currently unplayable. All we need to do if we want to play them, though, is remove the '& ' from before the filename, so the above entry becomes:
13 8MF1WF.tie TIE Fighter Challenge
Now there are a whole lot of new melee missions available to play!
Finally, let's add two more missions that were included in BoP, but do not have entries in the mission.lst file and therefore are currently unplayable.
The last line under [Free-for-alls] is
Furball with 2 Four-Man Teams
On the next line, add the following:
34 8mf4w01.tie Four Deuces vs Four Deuces 35 8mf4w02.tie Four on Four plus One?
This adds two more missions to your play list.