An Era II technology exclusive to the Necrophages which unlocks the ability to sacrifice a City's population to gain a temporary boost to Approval. Upon unlocking this technology, the City Info panel will gain a new button placed between the Population counter and the Growth Stock progress bar. Upon pressing this button, 1 Population will be sacrificed and the city will get a +30 bonus. This bonus will last a number of turns equal to the total Population of the City (including from pacified Villages) at the time of the sacrifice. Another sacrifice can be made before the effect from the previous one times out, and the duration of the effect will be extended by a number of turns equal to the population of the City.
If you play with the Endless Legend Community Patch, the duration scales with game speed as follows:
Fast: 1 turn per
Normal: 2 turns per
Slow: 3 turns per
Endless: 4 turns per
Hunger - for Food, recognition, or glory - can drive one to extreme behavior.