Restraint

Restraints can be built from chains or ropes. They can be used to tie up guard non-pet animals, prisoners, criminals or livestock.

Unlike a cage, a restraint can only hold one creature, and the creature can move within a range of one tile from the location of the restraint itself, including up and down if stairs or slopes are in this area. This gives them, at most, a 3x3x3 cube of movement, limited as normal by walls, doors etc. Restraints do not block movement, including movement of wagons. While an animal is assigned to it the same as with a cages, dwarves can only be chained as a punishment from within the justice system.

Restraints can be used to keep a war dog or other animal near areas where you need constant vigilance and defense. Chained animals placed near the entrance to your fort will spot kobold thieves that can bypass traps and other passive defenses, pausing the game and announcing their presence. A pair of animals, placed opposite each other against the walls of a 3-wide corridor (so they cannot have more than 1 tile between them), are guaranteed to spot any thief that tries to enter, and (if combative) will similarly engage any hostile creature. But assigning a pasture for the guard animal is more resource efficient way to guard specific areas. This also allows the animal to walk away on its own if there ever is an alert that forces everybody to a certain area.

Animals on restraints can breed, unlike animals in cages.