Walls add a separate blue health bar to each city, and here’s the key: Regular units can’t do much damage to cities that have walls. The key to conquering and sieging cities in Civ 6 is understanding how walls work. But any city more advanced than that will decimate your units if you aren’t properly prepared. Taking over a city without walls or encampments is basically the same as it used to be throw your units against it for a while until it falls. Wartime city mechanics in Civilization 6 are derived from those in Civ V, but expand on them dramatically-in a way that makes cities much harder to conquer if you don’t know what you’re doing.
