 Thus, a mountain route may be graded 5.6 (rock difficulty), A2 (aid difficulty), WI3 (ice climbing difficulty), M5 * (mixed climbing difficulty), 70 degrees (steepness), 4000 ft (length), VI (commitment level), and many other factors.See also Summitpost Alpine Grades.In contrast to the French numerical system (described earlier), the French adjectival alpine system evaluates the overall difficulty of a route, taking into consideration the length, difficulty, exposure and commitment-level of the route (i.e., how hard it may be to retreat).