|Vertical and horizontal anti-magic garrisons as seen on the Adventure Map.|
Anti-magic garrison is an Adventure Map object, that can withhold up to seven different stacks of creatures. The garrison prevents all spellcasting in the visiting square. This means that it is impossible for heroes or creatures to cast spells during a combat which takes place within the garrison, but it also prevents adventure spells to be cast while the hero is located in the visiting square. If an hero is attacked while located in the visiting square, the battle will take place inside the garrison and no spells can be cast in combat. Otherwise, the combat in the anti-magic garrison does not differ from a normal combat on the Adventure Map.
The anti-magic garrison can belong to a specific player or it can be neutral, in which case the flags are grey. An enemy hero can not pass the garrison without fighting the armies inside, and no hero can pass a neutral garrison without a fight. The garrisons can be aligned both horizontally and vertically, and they are typically used in narrow passes to create an obstacle, which can not easily be passed.
Additionally, the map-maker can set troops in the anti-magic garrison to be unremovable. This means that the specific player for whom the garrison belongs to, can not move the troops from the garrison to a visiting hero. This also means, that any troop stacks (from any player) transfered to the garrison will stay there permanently.