Quasars are the most luminous persistently emitting objects in the Universe. Powered by accretion onto a supermassive black hole, many of their observable properties should be determined by the fundamental parameters of accretion: the black hole mass and accretion rate. The black hole mass and accretion rate should, in turn, determine the shape of broad-band continuum emission arising from the accretion disk in the central engine. That broad-band continuum is responsible for powering the strong, broad emission lines that are prominent in optical and UV spectra, and are an identifying feature of active galaxies and quasars. Thus, the line emission may be used as a probe of the fundamental intrinsic properties, if we can break the code. I will present recent work investigating the role of the spectral energy distribution in determining AGN broad-line properties.