Bouldern: The Bouldering ABC – All Key Terms Explained
Crimp, sloper, beta, twisting in: the Bouldering ABC explains every key term in plain language before your very first day at the wall.
Sport: Bouldern · Level: Beginner
Introduction
"Can someone explain that in plain English?" If you walk into a bouldering gym for the first time and hear someone say "crimp the sloper, then twist in," you can feel like you've wandered into the wrong movie. It's not rocket science once you know what the words mean, though. This glossary walks you through the key bouldering terms in plain language — after reading it, every other DOMISPORTS bouldering guide will suddenly make sense.
Gear: What you need for hands and feet
Climbing shoes (Kletterschuhe): tight, purpose-built shoes with sticky rubber soles that fit like a second skin. Comfortable rental shoes are totally fine to start with — you don't need to suffer through pain.
Chalk (magnesia): the white powder you slap onto your hands before a move. It dries sweat and boosts friction on the holds, much like gymnasts use it on the bars.
Chalk bag (Chalkbag): the small pouch on your harness or on the floor that you dip your hand into between attempts to re-chalk.
Crash pad / bouldering mat (Bouldermatte): the thick, padded mat under the wall that cushions your fall. Indoors it's built into the floor; outdoors on real rock you carry it on your back as a "crash pad."
Climbing brush (Kletterbürste): a soft brush you use to sweep excess chalk off holds so they grip well again.
Wall & holds: The basic vocabulary
Boulder: this is what the individual route itself is called. A boulder consists of a start hold, a finish hold (the "top"), and every hold in between — usually marked by a shared color.
Top: the final hold of a route, which you have to reach and hold under control for the boulder to count as sent.
Grade: the difficulty level of a boulder, usually marked by color or number. Grades are only comparable within the same gym, never between different gyms.
Jug (Henkel): a big, comfortable hold you can wrap your hand around almost like a door handle — every beginner's best friend.
Sloper: a rounded hold with no real edge at all, which you hold purely through friction and body tension, like gripping a smooth doorknob.
Crimp (Leiste): a narrow, small edge you can only grab with your fingertips.
Volume: a large, usually geometric shape bolted onto the wall that has no hold texture of its own but often carries holds or serves as a foothold.
Sidepull: a hold that only grips cleanly from the side. You have to counter it with your body position, or it swings you off the wall.
Pinch: a hold you squeeze between thumb and fingers like a clothespin, instead of simply wrapping your hand around it.
Grip technique: How to actually hold the holds
Open hand (offener Griff): your default grip as a beginner — fingers stay fairly straight, only slightly bent. Easy on your finger tendons, and your go-to mode for endurance on the wall.
Half crimp: your middle finger joints bend to roughly 90 degrees — used on small edges once the open hand grip isn't enough.
Full crimp: the extreme version, with sharply bent fingers and the thumb locked over the index finger. Powerful, but risky — as a beginner, avoid it until your tendons have caught up with your strength.
Movement: How you move on the wall
Center of mass (Körperschwerpunkt): the point around which your weight is distributed, roughly at belly-button height. The closer it stays to the wall, the less your arms have to pull.
Three-point rule (Drei-Punkt-Regel): the basic rule for stability — you always keep three of your four limbs on the wall while moving the fourth.
Straight-arm climbing (am langen Arm klettern): hanging from a hold with a straight rather than bent arm, so your skeleton does the work instead of your muscles. The opposite is lovingly called "T-rex climbing."
Twisting in / back-step (Eindrehen): rotating your hip toward the wall and standing on the outside edge of your shoe — this gains you reach and saves strength.
Barn-door effect: the unwanted swinging of your body away from the wall, like a barn door on a hinge, when you're missing a counter-movement to stay balanced.
Traversing (Traversieren): climbing sideways along the wall instead of upward — great for warming up and building movement feel.
Pump: the burning feeling in your forearms once they're overloaded and your fingers start opening almost on their own.
Zip: an uncontrolled slip of a foot or hand off a hold or foothold.
Tactics & safety: Before and during your climb
Reading the route / beta: analyzing a boulder from the ground — which holds, which order, which body position. "Beta" is climbing slang for exactly this movement plan.
Project: a boulder that's (still) too hard for you, one you work on across multiple sessions instead of sending it in a single attempt.
Fall zone (Sturzraum): the area under and around a climbing person that must always stay clear — no bags, no bystanders, no walking through.
Spotting: guiding and cushioning a climber's landing from the ground, especially useful on the first high or dynamic moves.
Dyno: a dynamic, jumping move where you briefly lose all contact with the wall to reach a far-away hold.
Flapper: a torn flap of calloused skin on your palm that painfully folds back — the classic climbing blister, usually caused by damp or neglected skin.
Pro tip
Treat this glossary like a mental flashcard deck: the next time you hit "sidepull" or "crimp" in a guide, flip back here. After two or three sessions in the gym, the vocabulary sticks on its own — because you'll feel these terms in your own body, not just read them.
FAQ
What is "beta" in bouldering?
Beta is climbing slang for the movement plan of a boulder — which holds you use, in what order, and with what body position. Experienced climbers often read the beta from the ground before they even start climbing. Getting beta from someone else can save you a lot of frustrating trial and error.
What does "crimp" mean in bouldering?
A crimp is a small, narrow edge you can only grab with your fingertips. Depending on how sharply you bend your fingers, this splits into open hand, half crimp, and full crimp. As a beginner, favor the open hand — the full crimp puts extreme strain on your finger tendons.
What is a sloper?
A sloper is a rounded hold with no real edge at all — you hold it almost entirely through friction and a low, engaged body position, not raw finger strength. Slopers feel impossible at first, but become surprisingly manageable once your body tension improves.
What does "twisting in" mean in bouldering?
Twisting in means rotating your hip toward the wall and standing on the outside edge of your shoe instead of staying square to the wall. It gains you extra reach, saves strength in your arms and fingers, and keeps you more stable on overhangs. It's the single most important technique beyond raw power.
What's the difference between a boulder and a route?
In bouldering, people usually say "boulder" instead of "route" — they mean the same thing: a fixed sequence of same-colored holds from start to top. "Route" technically comes from rope climbing, but climbers use it interchangeably with "boulder" all the time.
Key Takeaways
Boulder, top, beta, crimp: knowing these core terms means every bouldering guide instantly makes sense.
Every hold name hides real technique – open hand, half crimp, and sloper show how differently you need to grip each one.
Safety vocabulary like fall zone, spotting, and zip isn't climbing slang to show off with – it protects you from your very first session.