Construct

Constructs, also called golems or homunculi, are magically created entities that serve as a source of labour. Although typically humanoid, they can come in all shapes and sizes.

The creation of a construct is a large magical endeavour, and only those talented in conduit magic are capable of it. The components of a successful construct are: The existence of constructs, even simple ones, necessitates large amounts of ambient magic. As a consequence, the creation of constructs have been functional impossible for the majority of Gondalan history.
 * body - the physical form of the entity, usual materials include metal, wood, clay;
 * operating sentience - set of mental instructions (class Ib spirit) for moving the body, such as walking, performing actions with hands etc;
 * intent - a purpose for the construct to work towards, a Class IIb spirit, essentially the "soul" of the entity;
 * bond - some way of binding the intent and operating sentience to the body;
 * energy source - a way to provide the construct with physical energy required for movement and other actions.

Energy source
Constructs require an energy source to power their actions. Usually the energy source is external, and there is a magical link that transports the energy from the source to the construct. However, internal or portable energy sources are theoretically completely plausible.

Possible energy sources include: Often times, severing the link between the energy source and the body is the most efficient (but also the riskiest) way to neutralise a construct. Depending on its operating sentience, a golem, cut off from the energy source, will either instantly stop operating, or try to find a closer, immediate source of energy. This usually means drawing out environmental thermal energy, causing the temperature in its surroundings to drop drastically, or encouraging spontaneous matter-energy conversion, usually causing an explosion.
 * a waterwheel or a windmill producing mechanic energy;
 * a bonfire or volcanic hotspot providing thermal energy;
 * a lightning storm producing electric energy;
 * direct matter-to-energy conversion, releasing nuclear binding energy.

It seems that, unless specifically instructed not to do that, a golem will usually try to find a new source. For this reason, it is highly advised against disconnecting random golems from their energy sources.

Dyrfell
The Dyrfell are ancient, Elven golems. Some of them may or may not have survived in inactive states up to times when the levels of magic rose enough to support their operations again.