Zone of control (abbreviated ZOC or ZoC) is a game mechanic in Civilization VI and its expansions that affects unit movement. It prevents a unit that is adjacent to an enemy unit from moving directly into any tile that is also adjacent to an enemy unit, unless a friendly unit is in the destination tile; attacks against units in said tiles can be made normally, however.
Many units and certain districts exert zone of control against all hostile units - specifically, those of Barbarians, Free Cities, and any civilization or city-state with which their owner is at war. They are:
- Melee units (including Persian Immortals)
- Anti-cavalry units
- Light cavalry units
- Heavy cavalry units
- Ranged units with Suppression
- Warrior Monks
- Giant Death Robots
- All naval units
- City Centers
- Religious units (against other religious units only)
Under normal circumstances, a zone of control affects all adjacent tiles in the unit's native element - in other words, land units (whether on land or embarked) do not exert zone of control on water tiles and naval units do not exert zone of control on land tiles. City Centers, Encampments, and Oppidums, however, exert zone of control on all adjacent land and water tiles, and embarked land units exert zone of control on the tile they occupy, which can be helpful when trying to put a coastal city under siege (a city is considered to be under siege when all 6 tiles next to the City Center are either impassable terrains or subjected to a zone of control).
Units cannot exert zone of control on tiles across a River. They can, however, exert it against districts, including City Centers, Encampments, and Oppidums.
A unit entering a zone of control cannot move another tile until after it attacks an adjacent unit or city. The unit can also perform other actions like Plundering Trade Routes, Pillaging, or promoting if it has enough Movement left. However, civilian units like Settlers and Builders cannot settle new cities or expend a Build Charge when they are within a zone of control. Additionally, Great People cannot activate their unique abilities on the same turn that they enter a zone of control, as all Movement is lost upon entering.
Units that enter a zone of control can still attack like normal, if they have enough Movement left to perform the attack. Units with innate abilities or promotions that allow them to move after attacking can leave the zone of control within the same turn that they enter, if Movement allows. Therefore, this ability is actually stronger than it sounds, especially for units with a ranged attack (such as upgraded recon units).
A unit that starts its turn within a zone of control can always leave the zone, as long as it has not moved or attacked that turn. If it moves into another zone of control, it will be subjected to the normal zone of control rules.
There are units that ignore zone of control completely. They are:
All civilian units, support units, and Great People are affected by zone of control. However, when in formation with a unit that ignores zone of control, the non-military unit also ignores zone of control.