Hi, does it have subtitles? English is not my main language and its difficult to understand when playing. If it has English subtitles Im happy.

No subtitles, sorry.

You can read all the emails and logs in your MFD by clicking on the respective entry.

Anyone know if there's any mods that add CCs/subtitles to this game? I know older PC games greatly lacked this sort of functionality, but I'm hoping there's some way I can play this game despite being unable to understand what's being spoken aloud.

No, there is none.

Of course there is some Spanish subtitles..............

academia. clandlan. net/?page=academia/view&id=1&title=Traduccion_de_System_Shock_2

pd: Ahi tenés algunos subtitulos para jugarlo en español, faltan de las voces, asi que tocará afinar los oidos... pero algo es algo, que lo disfrutes..

+rep a ClanDLan como siempre..

Thanks all for the answers.

Is it playable without understanding audio (without subtitles)?

Do you want to know if you can finish the game without knowing what's going on or if not relying on the audio is possible? If it's the first: Very unlikely. If it's the second one: Yes, as has been said, (almost) every bit of audio in the game can also be read so you do not have to have a great listening comprehension.

Also, do note that besides the English and German versions obtainable from GOG, fans have translated the game's text to Russian, French, Spanish and Czech, search for them here:
https://www.systemshock.org/index.php?board=2.0