A crux in

climbing Climbing is the activity of using one's hands, feet, or any other part of the body to ascend a steep topographical object that can range from the world's tallest mountains (e.g. the eight thousanders), to small boulders. Climbing is done fo ...

mountaineering Mountaineering or alpinism, is a set of outdoor activities that involves ascending tall mountains. Mountaineering-related activities include traditional outdoor climbing, skiing, and traversing via ferratas. Indoor climbing, sport climbing, a ...

and

high mountain touring A high mountain tour (german: Hochtour) is a mountain tour that takes place in the zone that is covered by ice all year round, the nival zone. High mountain tours require special preparation and equipment. Alpine ''Hochtour'' In the Alps a hig ...

is the most difficult section of a route, or the place where the greatest danger exists. In

sport climbing Sport climbing (or Bolted climbing) is a form of rock climbing that relies on permanent anchors (or bolts), permanently fixed into the rock for climber protection, in which a rope that is attached to the climber is clipped into the anchors to ...

and

bouldering Bouldering is a form of free climbing that is performed on small rock formations or artificial rock walls without the use of ropes or harnesses. While bouldering can be done without any equipment, most climbers use climbing shoes to help sec ...

, the most technically challenging point in the climb is also called the ''crux'' section. In describing a

climbing route A climbing route is a path by which a climber reaches the top of a mountain, rock, or ice wall. Routes can vary dramatically in difficulty and grade; once committed to that ascent, it can sometimes be difficult to stop or return. Choice of rout ...

using a

topo Topo or TOPO may refer to: * Topo (Calheta), a civil parish in the municipality of Calheta, in the Portuguese archipelago of the Azores * Topo (climbing), in climbing, a guide for a crag or climbing area * Topo (robot), a robot aimed at the consu ...

, cruces (or cruxes) are usually shown with a key symbol. The

grade Grade most commonly refers to: * Grade (education), a measurement of a student's performance * Grade, the number of the year a student has reached in a given educational stage * Grade (slope), the steepness of a slope Grade or grading may also ref ...

of a climbing route is based on the technical difficulty of the crux (e.g. in the sport climbing system, or in the bouldering system), and for

traditional climbing Traditional climbing (or Trad climbing) is a style of rock climbing in which the climber places all the necessary protection gear required to arrest any falls as they are climbing, and then removes it when the pitch is complete (often done ...

routes, an additional grade is used for the risk of personal injury to a climber of a fall at the crux (e.g. the British E-grade system). That means the rest of the route might be considerably easier, however, a route may comprise several cruces of equal difficulty, or simply be a route of a very consistent level of difficulty with no sections that stand out as harder than the rest. In planning a route it is important to know how far it is before the crux is reached, because cruces (or cruxes), can only be overcome with sufficient reserves of strength.Kurt Winkler / Hans-Peter Brehm / Jürg Haltmeier: ''Technik, Taktik, Sicherheit'', SAC Verlag 2008, {{ISBN, 978-3-85902-280-5, pp. 84 ff. Sport climbers have come to use a

kneebar A leglock is a joint lock that is directed at joints of the leg such as the ankle, knee or hip joint. A leglock which is directed at joints in the foot, is sometimes referred to as a foot lock and a lock at the hip as a hip lock. Leglocks are f ...

to rest before, or immediately after, a crux; they can also continually practice a crux using

top roping Top rope climbing (or top roping) is a style in climbing in which the climber is securely attached to a rope which then passes up, through an anchor system at the top of the climb, and down to a belayer at the foot of the climb. The belayer takes ...

References

Mountaineering Climbing