These affect your rep with the given faction:
event = object_destruction, -0.030000 Rep goes down
event = random_mission_success, 0.085900 Rep goes up
event = random_mission_failure, -0.045000 Rep goes down
event = random_mission_abortion, -0.067500 Rep goes down


The following entries affect your rep with the other factions in the game.
Think of it as "the friends of my friends," or "the friends of my enemies," or "the enemies of my enemies."

Hurting the given faction causes your rep with this one to go up:
empathy_rate = li_lsf_grp, 0.400000

Hurting the given faction causes your rep with this one to stay the same:
empathy_rate = br_n_grp, 0

Hurting the given faction causes your rep with this one to go down:
empathy_rate = fc_ou_grp, -0.400000


Watch your 6!

Thank you very much!

about intialworld.ini...

If I wanted to add a faction, would I have to add an entry of that faction to every other faction? (i want to make my new faction enemy with all, and make it so that they will fight)

and would their empathy.ini entry have to have all the mission stuff, and changing reps with other factions? i.e. it only mentions what happens if you destroy their stuff.

1) You're Welcome!
2) YES! Otherwise, the player would be the only one to react to your faction. There would be no battles between them, and other factions. IIRC, Freelancer will crash without them.
3) YES! Otherwise, the player's rep would be constant. Also, the relationship to other factions determines who will attack them/aide them during battles, and will affect who will be pissed at you, or like you more, for attacking/aiding them. IIRC, Freelancer will crash without them.

I tried adding new factions earlier in my modding days, but found it much easier to simply modify existing factions.
(There are numerous, seldom used factions, available in the game.)
And, as your inquiry implies, it's a ton of work, adding new factions.

You've got to add them in:
NPCships.ini
InitialWorlds.ini
Empathy.ini
mBases.ini
Faction_Props.ini
KillableSolars.ini
VignetteParams.ini
RMLootInfo.ini
commodities_per_faction.ini

(And those are just the ones I can remember, right now.)

Watch your 6!

"If I wanted to add a faction, would I have to add an entry of that faction to every other faction?"

Technically no you don't have to, reputations and empathy rates will both default to 0 (neutral) if you don't specify them.

Thanks. Fortunately, the faction I'm adding won't have any bases, just encounters, so I think I'll be able to get away with only NPCships.ini, empathy.ini, initialworld.ini. Not sure about RMloot and commodities per faction, so thanks for the heads up!

@Xen()morph

Keep in mind that added factions will only interact with other factions in MultiPlayer! In SP, added factions will fly around and do their stuff, but they will be neutral towards all the other factions. They will shoot back at the player if they are attacked, but it just seems that SP doesn't read added factions' values in InitialWorld.ini so they'll have no enemies and no friends. So unless you want to create a Space Hippie ("live and let live" faction, you'll need to work around this fact.

*(I'm talking about OpenSP now, both the classic version and Argh's alternative version. Maybe this isn't true for normal "storyline" SP. I never tried.)

So, if you're making some sort of an OpenSP mod, then you'd better use one of the minor factions, like fc_ouk_grp or fc_f_grp**. You'll need Anton's rep list hack to make them appear on the rep list, as those factions are normally blocked: Open common.dll in a hex editor (like Hex Workshop), search for the nickname of the faction you want to unblock (like fc_f_grp) and replace its nickname with dots .....

**(Of course, these factions play a role in the storyline, so you can't alter them without screwing up the SP storyline. But then again, maybe adding completely new factions isn't a problem at all when the player goes thru the storyline).

These setup missions that are offered on bases by the npc's:
KillableSolars.ini
VignetteParams.ini
RMLootInfo.ini
If you're only going to have encounters, you can ignore them.

Watch your 6!

@Moonhead: Thanks! I wasn't aware of that! Now I understand why they didn't do anything when they're ships spawned. I'll probably use one the nomads 'cause they're already enemy with everyone. Thanks!

You're welocme. I'm not sure but I think it was Harrier who explained this, a looong time ago...