People of Eminiar VII who waged a five-hundred-year war with Vendikar by computer, with simulated casualties reporting to real disintegration chambers.
The Eminians live on Eminiar VII, a technologically advanced world in a centuries-long war with its neighbour Vendikar. To spare their cities, the two planets agreed to fight entirely by computer simulation. When an attack registered, the citizens counted as casualties walked willingly into disintegration chambers, keeping their civilization intact while the death toll mounted.
When the Enterprise arrived on a diplomatic mission, the computers declared the ship a casualty and Eminian leader Anan 7 demanded the crew report for disintegration. Kirk refused and destroyed the war computers, forcing both sides to face the true horror of war and opening the way to peace talks.