A flash is climbing a route or boulder problem cleanly on your first attempt, but with the benefit of beta gathered beforehand — watching someone climb it, getting hold descriptions, or studying video. It ranks just below an onsight, which allows no prior information at all.
An onsight is climbing a route cleanly from bottom to top on your very first attempt, with no prior practice, no beta, and no watching others on it. It's considered the purest and most prized ascent style, because you solve every move in real time without any foreknowledge.
A gaston is a grip where you push outward (sideways, away from your body) on a hold with the thumb pointing down and the elbow out, as if prying open elevator doors. It lets you use vertically oriented holds that face the wrong way for a normal pull, but is shoulder-intensive.
Flagging is a balance technique where you extend a free leg to act as a counterweight, keeping your body in balance and stopping it from swinging out (barn-dooring) when holds are off to one side. It lets you reach and stay stable without a foothold for the trailing foot.
Mantling is a technique where you press down on a ledge or large hold with your hands — transitioning from pulling to pushing — to lever your body up and over it, much like climbing out of a swimming pool. It's the standard way to top out boulders and gain ledges.
Jamming is the core crack-climbing technique of wedging part of the body — fingers, hands, fists, or feet — into a crack and subtly expanding or torquing it to create a secure hold. Unlike face climbing, jamming uses the crack itself rather than holds on the rock surface.
A sloper is a smooth, rounded hold with no positive edge to grab, gripped instead through friction from an open hand and careful body positioning. Climbers maximise skin contact and keep their weight below the hold, making slopers as much about technique and tension as raw strength.
A crimp is a small, narrow hold that offers only enough room for fingertips, and the technique of gripping it. Climbers bend the fingers at the knuckles to load the edge, using an open, half, or full crimp depending on the hold. Crimping is powerful but a leading cause of finger injuries.
Smearing is a footwork technique where you press the sole of your climbing shoe flat against the rock to grip through friction, rather than standing on a defined hold. It's essential on slabs and featureless faces, relying on sticky rubber, body position, and trusting your feet on seemingly blank rock.
Edging is a footwork technique where you stand on a small hold using the stiff edge of your climbing shoe, usually the inside edge near the big toe. It gives precise, powerful purchase on tiny ledges and crystals, and works best on vertical to slightly overhanging rock with defined footholds.