Abstract
A brief survey is given on the physical properties of heavy-fermion metals, i.e. certain lanthanide- and actinide-based intermetallic compounds. The origin of the heavy electron masses and the formation of both magnetically ordered and coherent Fermi-liquid states, including the Fermi surface properties of UPt3, are discussed. Particular emphasis is put on the phenomena and problems associated with the occurrence of superconductivity in CeCu2Si2 and UBe13 as well as their counterparts UPt3 and URu2Si2.