We study how the regolith properties affect the measured fluorescent soft X-ray spectra from atmosphereless planetary surfaces as a function of mean particle size and particle size distribution, surface roughness and viewing geometry. The relative fluorescent elemental line intensities from the X-ray spectra measured from a planetary surface can be used to determine the geochemistry of the surface. Regolith particle size distribution, surface roughness and viewing geometry all have their effects on the observed spectrum of the fluorescent radiation. The study utilizes numerical simulations and laboratory measurements to analyze the significance of these effects on planetary soft X-ray fluorescence spectroscopy We have developed a ray-tracing X-ray code which simulates the fluorescent signal induced by incident X-Ray flux from a regolith consisting of spherical particles. The spectrum of the incident radiation, medium properties, and the elemental composition of the fluorescing material can be freely given by the user, and several simulation methods are available starting from a fast first-order fluorescence method to a full-blown Monte-Carlo simulation. Effects due to particle size distribution and medium porosity can be simulated together with the effects due to larger-scale surface roughness introduced as two-dimensional statistical random fields.