The purist version only adds fixes for a lot of bugs that vanilla has. Full adds new content to the game. Custom is just so you can cutomize everything in the mod (i.e. what new content you want and what content you do not want).

From what i rember even the purist still does not only fix bugs, it also gives for example you weapons to the things you tagged in the cc. Might better off looking for the unofficial patch if you wanna play it as a purist. Also active the hi-rez patch in your folder. But imo it is pretty playble without patches.

So does this mean I should use Purist or an unofficial patch? If patch, then whose? If Fixit, then where can I find a list of the fixes?

Strange question. There is only one unofficial patch for FO1 by TeamX. Fixit is bult on top of that patch.

Well, tricky part is that actually there are three patches by TeamX:
* semi-official 1.2 for the US disk versions of the game,
* semi-official 1.2.1 unified for all and every English-speaking versions (including UK and multilingual)
* unofficial 1.3.5 for all English-speaking versions

Semi-offical patches are the 'ultra purist' since those are just a compilation of the official fixes from the different game distributions collected in the one package. Unofficial patch is a fans' work which further fixes the game's bugs. It is 'purist' without any extras.

Patches are NOT cumulative therefore, depending on distribution you own, you have to install one of the semi-offical first and on top of that the unofficial one. There is no convenient installer like in the Fixit and everyting should be done manually. That's why those patches are relatively unpopular amoung 'common people'.
If you have modern electronic version of the game purchased from GOG or Steam, use 1.2.1 RC as a semi-official patch! Despite beeing an RC it's actually complete. And fixes some important problems which are not addressed in the earlier 1.2. Otherwise you most probbaly will get completely umotivated hostility from all NPCs in Junktown and lose chances for peaceful negotiations.

Can't definitely advise for or against the Fixit since never used it personally. You still should see what unwanted modifications it includes even in a purist mode.
The facts are:
* Fixit includes all and every official patches by Interplay released till far
* Fixit includes all semi-official patches by TeamX
* Fixit includes all unofficial patches by TeamX, some fixes are altered or rolled back by a popular demand, though
* Fixit definitely introduced some more 'purist' bugfixes which were not addressed by TeamX' patches
* Fixit includes some controversial 'fixes'. Which either can not be confirmed as an original developers' (mis-)intetions or design flows; or can not be considered well fit for the released game.

Full list of modifications included in the TeamX' patches is included in every package. Full list for the Fixit is not as easy available. You probably should read wiki of the project and corresponding topics in NMA forum system for the clues.

Wow!

Thank you for taking the time to be so detailed! I'll admit that I am a bit overwhelmed here.

Yes, I did buy the GOG version and I wanted to get into the series starting with the first game but heard of some of the issues it still had and I really only plan to play it once or twice and so was looking for the best way to set it up.

So 1.2.1 RC is what you reccommend? Is it easy to find and also does RC stand for anything? And you're saying Fixit includes a lot of extras that may not be "pure" so it may warrant further investigations since the info is not as acessible as TeamX's. I'll look into both this semi-official patch and more into Fix-it!

If there are improvements that move away from being "pure" I am definietely interested in those.

Sorry for all the questions and thank you for your help so far!

Sorry! I was probably confusing in my wording earlier by puting too much empasis on "pure" so it's my fault for any misunderstandings. You gave me a lot of interesting information and no blabber!

Also, thanks thijsjan44 and cristoforo_93 as well!

And I missed seeing those links you sent in your replies; sorry about that as well. I think I understand now and just need to decide between the two styles. I've been looking for such a clear distiction and this will help in my decision making.

Thank you for all this and thank you for your time! I really appreciate it and will keep this all in mind. ^_^

Selecting Custom and setting everything for yourself is obviously the safest, but may give you some mild spoilers. The only thin you NEVER want to check is the "Just for fun" section, which actually messes with some of the canon content, but I think that's unchecked by default in every other installation, so it's OK to just use Full if you want the simplest option.

There's nothing else that messes with the original actually, the whole patch are largely quality of life improvements, like: quests and endings that were bugged and impossible to complete, restored; other content that was in the game files bit didn't get implemented in the release, restored; some features added in Fallout 2 (like the "Take all" inventory option to speed up inventory management); improved companion commands (like "Get out of the way!" so that they won't block your path anymore :p ) or the ability to equip companions with every weapon/armor (finally giving them a chance of survival during the finale).
The thing is 99% of this will probably annoy you in the original and 99% was also likely intended by the developer team if they had more time to fix bugs and finish content.
So you really don't have a reason to not use them and play in Purist mode, except if you're say, a game reviewer and want to give the game a score without the fixes. As a player, your experience is only going to be enriched by these changes.

Or you are playing the game for the first time.

Yongsters nowadays have forgotten the reason why the picture below is a sufficient cause to hold Fallout 2 from "Number one CRPG of all times" title, for example. ))))