Not to be confused with "Core Worlds" in Stellaris, other Paradox titles use a system of Claims and Cores to show vested ownership of territory.
I think Stellaris should adopt a similar system. Both Empires and Sectors would be able to have claims and cores. After 50 years of a system being in an Empires territory that empire gets a claim on a world. After another 50 years that claim becomes a "Core" (might need to be called something else due to Core Worlds)
A core would mean that the rest of the galaxy essentially recognizes it as a part of your empire. If it is taken in war it's cheaper to get back. Nationalist factions form trying to return captured cores to their home empires.
If a sector is captured by en enemy, factions may form to re-form the original sector under the new ruler is a sector had a core there.
Claims are lost if an empire doesn't control it for 100 years. Going to war over the claim resets this clock even if you lose the war.
This can also create new wargoals and peace options. For example you can demand that an enemy empire give up claims or cores on worlds.
I think Stellaris should adopt a similar system. Both Empires and Sectors would be able to have claims and cores. After 50 years of a system being in an Empires territory that empire gets a claim on a world. After another 50 years that claim becomes a "Core" (might need to be called something else due to Core Worlds)
A core would mean that the rest of the galaxy essentially recognizes it as a part of your empire. If it is taken in war it's cheaper to get back. Nationalist factions form trying to return captured cores to their home empires.
If a sector is captured by en enemy, factions may form to re-form the original sector under the new ruler is a sector had a core there.
Claims are lost if an empire doesn't control it for 100 years. Going to war over the claim resets this clock even if you lose the war.
This can also create new wargoals and peace options. For example you can demand that an enemy empire give up claims or cores on worlds.