|This article is about an older version of DF.|
Mechanisms are created out of stone by a mechanic at a mechanic's workshop. They can also be forged from 3 adamantine wafers at a magma forge. Building traps, levers, and pressure plates requires one mechanism. Linking objects to a lever or pressure plate requires two mechanisms per linked item (one for the object, one for the lever). If you want to ever recover those mechanisms you need to deconstruct both the linked object and the lever.
It is a mechanic's job to install mechanisms. Mechanisms can be linked to objects at any distance.
Mechanisms make surprisingly good trade items, due to their high base value of 30, but are heavy compared to crafts and so may not be a good trade good for races who do not bring wagons. Since their value is higher than that of a statue, levers make good alternative room decorations.
Since mechanisms count as furniture, the jeweler's workshop action encrust furniture with [gem] can encrust mechanisms with gems instead of actual furniture.
High-quality mechanisms improve the accuracy of weapon and stone-fall traps, as stated by Toady here. This means traps will benefit more from high-quality mechanisms.
A mechanism's quality has no effect on how quickly it operates.