Factors and structural parameters of coatings influencing the efficiency of protective coating systems against rain erosion of wind turbine blades are reviewed. The possibilities to enhance the attenuation of wave energy from droplet impact, increase damping and varying stiffness, creating interfaces for wave reflection, adding reinforcement for wave scattering, and creating additional layers or skeleton‐like reinforcing or wave absorbing structures, are discussed in the paper. Formulas for quantitative estimation of these effects as well as qualitative relationships between the structural parameters of coatings and their performance are presented. Recommendations and promising directions for the improvement of the protective coating systems for rain erosion protection of wind turbine blades are presented.