Lead climbing (or leading) is a technique in rock climbing where the 'lead climber' clips their rope to the climbing protection as they ascend a pitch of the climbing route, while their 'second' (or 'belayer') remains at the base of the route belaying the rope to protect the 'lead climber' in the event that they fall. The term is used to distinguish between the two roles, and the greater effort and increased risk, of the role of the 'lead climber'.
Leading a climb is in contrast with top roping a climb, where even though there is still a 'second' belaying the rope, the 'lead climber' faces little or no risk in the event of a fall and does not need to clip into any protection as the rope is already anchored to the top of the route (i.e. if they fall off, they just hang from the rope). Leading a climbing route is a core activity in rock climbing, and most first ascents and first free ascents are from leading.
Lead climbing can be performed as free climbing, in either a traditional climbing or a sport climbing format — leading a traditional climb is a much riskier and physically demanding exercise for the climber. Competition lead climbing is a sport climbing format that is part of the Olympic sport of competition climbing. Lead climbing can also be performed as aid climbing. The term is not generally applied to free solo climbing, as the free solo climber is already alone and thus there is no need to distinguish the role of 'leader' from the 'second'.
Description
'Leader' (top) belayed by the 'second' (below)
Leading a route requires a 'lead climbing pair'. When ascending a route, the 'lead climber' of the pair clips their rope into the climbing protection as they progress up a pitch on a given climbing route. If they are leading a traditional climbing route, the 'lead climber' must arrange and insert 'temporary climbing protection' as they climb. If they are leading a sport climbing route, the climbing protection is already installed via pre-drilled bolts, into which the 'lead climber' only needs to attach quickdraws.[1][2][3] Leading a traditional route is, therefore, a much riskier and physically demanding undertaking than leading a sport climbing route of the same grade.[4]
'Leader' (top) belaying the 'second' (below)
Aside from the specific additional risks of traditional climbing, every 'lead climber' faces the specific risk of falling twice the distance to their last point of climbing protection — i.e. if the 'lead climber' was 3-metres above their last point of protection, then in a fall, they will fall over 6-metres, thus the rope starts to brake 3-metres below their last point of protection.[4] This aspect makes leading a more physically demanding activity than top roping where the lead climber is immediately held by the top-rope upon falling.[1][2]
Leading a climb also requires good communication between the 'lead climber' and the 'second' who is belaying. In particular, the 'lead climber' will want to avoid the 'second' holding the rope too tightly, which creates "rope drag" that acts as a downward force on the 'lead climber'. However, where the 'lead climber' feels that a fall is imminent, they will want the 'second' to quickly "take in" any slack in the rope to minimize the length of any fall. Once the 'lead climber' has reached the top of the route (or pitch on a multi-pitch climbing route), they will then create a fixed anchor and belay the 'second' from above as the 'second' climbs up, removing any temporary climbing protection that the 'leader' had inserted earlier; note that the 'second' is not themselves 'lead climbing' but are in effect, top roping (e.g. if they fall they will just hang from the rope).[1][2]
First ascent
The act, and drive, to lead a climb is related to the definition of what is a first ascent (FA), or first free ascent (FFA) in the traditional and sport climbing formats. The grades assigned to traditional and sport climbing routes are based on the climber leading the route, and not top roping it. If a climber wants to test themselves at a specific technical grade or set a new grade milestone, then they must lead the route.[1][2]
Before the arrival of sport climbing in the early-1980s, traditional climbers frowned upon FFAs where the 'lead climber' had practiced the route beforehand on a top rope (called headpointing), or worse still, practiced the crux moves from a hanging fixed rope (called hangdogging). The arrival of sport climbing led to the development of the redpoint as the accepted definition of an FFA, which includes the practices of headpointing and hangdogging. Where a 'lead climber' can complete a route first-time and without any prior knowledge, it is called an onsight (or a flash if they had prior knowledge) and this is still considered the most desirable form of ascent, and is separately recorded in grade milestones and climbing guidebooks.[5][6]
Risk
Lead climber falling with a modest runout from their last point of climbing protection; the 'belayer' is not visible but has clearly locked the rope so the climber is fulcruming around their last point of protection.
Aside from the specific risks involved in placing the temporary protection equipment while leading traditional climbing routes (i.e. and making sure that it won't fall out in the event of a fall), the 'lead climber' needs to manage several other general risks when they are leading a climbing route, such as:[1][2][4]
Runout is the distance from the 'lead climber' to the last point of protection. In any fall, the 'lead climber' will fall at least twice the distance of the runout (and sometimes more if the climbing rope has to flex, or if the belayer does not immediately grip the rope tight and lets more rope 'pay-out'). The greater the runout, the greater the total distance in any fall, and the greater the mental pressure on the climber. Some leads involve runouts where any fall could result in a "ground-fall" (or the leader "hitting the deck").[4][7]
Hitting obstacles during falls. Ironically, extreme climbing routes tend to be very overhanging (e.g. Realization or Silence), and thus where a 'lead climber' falls, they naturally avoid hitting any obstacles on the way down, until the rope holds. In contrast, on easier climbing routes, there is a greater chance of the 'lead climber' hitting against obstacles on the rock face as they fall, thus causing serious injury.[4][7]
Back-clipping is where the rope is clipped into a quickdraw in such a way that the leader's end runs underneath the quickdraw carabiner as opposed to over the top of it; if the leader falls, the rope may fold directly over the carabiner gate, causing it to open with catastrophic consequences.[4][8]
Z-clipping is where the 'lead climber' grabs the rope below an already clipped quickdraw and clips it into the next quickdraw, resulting in a "zig-zag" shape of the rope on the wall, which can create immense rope drag making further progress impossible until it is fixed.[4][8]
Turtling is where one of the 'lead climber's' limbs is behind the rope when they fall, which can result in the climber being "flipped" upside down (i.e. like a turtle on its back), which can then eject the climber from their harness, which is a serious event.[4][8]
Regardless of the particular type of format that the 'lead climber' is undertaking (i.e. traditional, sport, or aid), they will require a harness attached to one end of a dynamickernmantle rope (usually via a figure-eight knot). Their 'second'—who will be belaying—will use a mechanical belay device that is clipped into the climbing rope and which 'pays-out' the rope as needed as the 'lead climber' ascends the route, but which can immediately grip the rope tightly in the event that the 'lead climber' falls.[1][2]
Where the 'lead climber' is following a traditional climbing format, they will need to carry an extensive range of protective equipment (often referred to as a 'climbing rack' and is usually worn around the waist being attached to the climbing harness) such as nuts, hexcentrics and tricams (known as "passive" protection), and/or spring-loaded camming devices (or "friends", and known as "active protection"). Where the 'lead climber' is following a sport climbing format, they only need to carry quickdraws (which they will also attach to their climbing harness) that they will clip into the pre-drilled bolts along the sport route.[1][2][9]
Some indoor climbing walls provide in-situ mechanical lead auto belay devices enablig the climber to lead the route but belayed by the device. Typical versions belay the lead climber from above so the climber is essentially top roping the route, and does not need to carry any climbing protection.[10][11]
Longer climbing routes (e.g. as in big wall climbing), are usually led in series of multiple pitches of circa 35–50 metres (115–164 ft) in length. In multi-pitch leading, the two climbers can swap the roles of 'lead climber' and 'second' on successive pitches. The 'second' needs to be comfortable working from a hanging belay, and both need to be familiar with the process for swapping between roles safely and efficiently.[12] Given that average pitch length will be longer, and that the weather potentially poorer, both climbers need to communicate clearly, and know the climbing commands.[13]
On long but easier routes, the climbing pair may use simul climbing, whereby both climbers simultaneously ascend the route. The 'lead climber' acts like on a normal lead climb, however, the 'second' does not remain belaying in a static position, but instead also climbs, removing/unclipping the protection equipment of the 'lead climber'. Both climbers are tied to the rope at all times, and both make sure that there are several points of protection in situ between them. Simul climbing is performed on terrain both climbers are comfortable on, as any fall is serious; often the stronger climber goes second.[14]
