The subject of smoke control in buildings is being given greater attention as evidenced by the presentations in this symposium and other technical papers. Most major building codes today require smoke control to some degree. Based on code requirements, the aforementioned voluminous technical papers, and the ubiquitous engineering judgement, smoke control systems are being designed and installed in new and existing buildings. This paper will describe smoke control systems while recognizing that in spite of significant research in the development and movement of smoke in buildings, little substantial work has been conducted on how best to control smoke. Within this framework, the design engineer and his client are uncertain whether to regard the subject of smoke control in buildings as a threat or a promise.