For questions about the use of engineering to create structures and devices in other worlds, including whether or not a device could be made or what materials would be needed to make a device.
Engineering refers to the process of designing a physical element of a fictional world. It is the logical counterpart to architecture, and involves dealing with physical constraints, as opposed to making the element of a world aesthetic or culturally relevant.
Engineering usually applies to architecture questions, but the reverse is not always true.