The design of optical systems for high power lasers is ultimately constrained by the damage of optical surfaces due to the laser fluence. In CO2 laser fusion systems, the damage to copper mirrors in vacuum is attributed to melting produced by the absorbed laser energy. The Fresnel equations indicate that the use of metal mirrors at high angles of incidence (75-85 degrees from normal) results in reduced absorption of properly polarized light. This should lead to a commensurate improvement in damage resistance. Other benefits to be accrued include improved transmitted wavefront quality (for a given mirror figure error) and, of course, lower transmission losses. Application of glancing incidence concepts to advanced CO2 laser fusion systems will be described with emphasis on beam transfer and focusing mirrors. Applications to other systems at shorter wavelengths typical of the rare gas halide lasers will also be discussed.