It amplifies the effect of your influence in parsecs inside its radius, just like a Military Starbase amplifies attack and defence. All starbases have some sort of influence-creating ability inherent to them, because mining starbases I put down always have a zone of my influence around them. (The strongest influence effects of course come from the influence modules, but do they just add to the background influence or do they multiply it? --Varis)
They add the owner's influence in the area of the starbase - I know this because I've placed influence starbases in weakly influenced enemy areas (the area didn't have many planets around it but it was still a part of the enemy's territory) and gotten a circle of influence radiating fron the starbase (it wasn't thicker the closed it was to my plants) after a few upgrades --Your Friendly Neighbourhood Spiderman
The effect is greater the closer the starbase is to the planet.
IMHO Influence Bases work as intended. They don´t "make" i.e. create Influence, they just "repeat" it, like a loudspeeker. Your Empire creates Influence through its culture (Planets+special tiles). This is what gives you influence in the United Planets Forum, this is what people make trips to your worlds (Tourism). Influ Bases just repeat that in their area (make Planets deflect or keep them loyal) -- Blixa
New upgrade paths Edit
Since v1.1, the upgrade paths for Influencer Starbases have been changed - with poor and inaccurate documentation. The following information shall hopefully help you understand how things really are.
Originally there were two upgrade paths:
- Diplomatic Outpost
- Foreign Relations Center
- Interstellar Embassy
- Galactic Forum
- Supreme Forum
- Galactic Mall
- Xeno Concert Hall
- Interstellar Consortium
- Franchise Center
- Franchise Headquarters
- Cultural Maximaizing Center
- Insurrection Coordinator
- Cultural Conquest
The changes, as described by the official v1.1 changelog, are:
- - Eliminated Galactic Mall and Concert Hall starbase modules. Since influence victory strategies have been strengthened, we require players to have to go for the cultural domination tech path.
- - Put cost to upgrade an influence starbase at the beginning, subsequent modules are free.
- - Mining modules have been significantly nerfed since abilities are now directly multiplied rather than modified.
- - If you have the cultural domination techs, you can build directly to those upper cultural influence modules bypassing the wimpier lower level ones.
What the changelog however failed to mention is, now Galactic Mall and Concert Hall have been eliminated, it's still not possible to start upgrading an Influencer Starbase with Interstellar Consortium right away. Instead, you need to have upgraded to Interstellar Embassy for Interstellar Consortium to become available. (It's unclear if this is intended or a mistake, so it might change again when a new version comes out. The description below is at least applicable for v1.1 and v1.11.)
In other words, there are actually three upgrade paths now. The first and the second start with the same three modules (Diplomacy path):
- Diplomatic Outpost (Beware, upgrade cost!) (+5)
- Foreign Relations Center (+7)
- Interstellar Embassy (+10)
From here on, you can go for:
- Galactic Forum (+15)
- Supreme Forum (+25)
or straight ahead for:
- Interstellar Consortium (+20)
The third upgrade path is independent from the first two (Influence path):
- Franchise Center (Beware, upgrade cost!) (+25)
- Franchise Headquarters (+30)
- Cultural Maximaizing Center (+40)
- Insurrection Coordinator (+60)
- Cultural Conquest (+100)
The modules naturally stack, so a full Influence upgrade path will give you a +255 bonus.
As the first two paths both start with Diplomatic Outpost, you only have to pay once (500 bc in a Normal level). But since the third upgrade path is independent from the first two, you have to pay for Franchise Center (also 500 bc in a Normal level) again even if have already paid for Diplomatic Outpost.