Make it so ethnic and political events occur in systems with multiple populations, including:

  • ethnic hostilities between populations depending on race traits and history (defined by lore, random, or player actions),
  • political hostilities between different populations supporting different political parties, and especially between those supporting "arch enemy" political parties, like scientists vs religious,
  • hostilities between "superior" and "inferior" populations (basically major factions vs minor factions, or original population vs an enemy empire with same original population),
  • harmony between populations supporting same political ideology,
  • etc.