Open the descr_strat.txt, which lies insde your data/world/maps/campaign/imperial_campaign folder. The first lines should read:
Code:
campaign imperial_campaign
playable
romans_julii
romans_brutii
romans_scipii
end
unlockable
egypt
seleucid
carthage
parthia
gauls
germans
britons
greek_cities
end
nonplayable
romans_senate
macedon
pontus
armenia
dacia
numidia
scythia
spain
thrace
slave
end
Just cut + paste the factions you want from the nonplayble and unlockable sections into the playable section. To avoid some bugs, you should probably leave rebels and the senate as they are. So the final code would look like that:
Code:
campaign imperial_campaign
playable
romans_julii
romans_brutii
romans_scipii
egypt
seleucid
carthage
parthia
gauls
germans
britons
greek_cities
macedon
pontus
armenia
dacia
numidia
scythia
spain
thrace
end
unlockable
end
nonplayable
romans_senate
slave
end
The proceedure is the same in BI, but there you gotta be careful when it comes to emerging factions, as they require some more complex modding.
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