Rockfall hazard assessment without the use of rockfall trajectory and runout zone models is unthinkable in the 21st century. Such rockfall models have existed since the sixties, but nowadays an almost confusing palette of rockfall trajectory and runout zone models in 2- and 3-D exists. Each of those adapted to specific rockfall problems. This chapter will give an exhaustive overview of available rockfall models. In addition, it will present state of the art solutions for the integration of protective measures, either being technical structures or existing forest cover, in rockfall trajectory and runout zone models. Then, considerable attention will be given to a typical workflow, including its critical activities and milestones, for a combined field and modeling rockfall hazard study. The chapter will be finalized by a discussion of potential future improvements in methods for predicting rockfall trajectories and runout zones.