Why are climbers kept in isolation before they climb?
A · Advanced · Rules for every climber · 1 of 3Because working out how to climb the boulder is part of the test. In an on-sight round climbers may not watch anyone else on it or be given information about it. They get an official observation period to study it from the ground, and wait out of sight until called.
How it works
- On-sight: an attempt "made without any prior knowledge of the intended climbing sequence and without any prior practice".
- No watching: observing other climbers' attempts, or the routesetters at work, is prohibited.
- No coaching: team officials must not pass on information about the boulders until the climber has finished the round.
- Observation: climbers may look and may touch the starting holds, but "must not practice any moves".
- How long: two minutes for each boulder before the final.
- What may be touched: only the marked starting holds and their blocker holds.
- Allowed aids: binoculars and hand-written notes or sketches. No photographs or recordings.
- Sharing: climbers may share what they saw with each other only if neither has yet attempted the boulder.
- Flash rounds: the boulders are demonstrated beforehand and coaches may give information.
- Waiting: climbers stay in the warm-up area from its closing time until called. Leaving without permission means DNS.
- Breaking it: gathering information beyond what the rules allow is a disqualification offence.
The glossary has the onsight entry, the flash entry, the observation period, the isolation zone, route reading and beta.
Tricky cases
A climber who has finished tells a team-mate still waiting how to do the crux. Is that allowed?
No. Information may be shared only where neither has attempted the boulder, or where both have finished.
Can a climber photograph the boulders during observation to study in the warm-up area?
No. Notes and sketches are allowed, photographs and recordings are not.
The venue is outdoors and the wall can be seen from the street. Can a climber look at it beforehand?
Yes, from areas open to the public. They may not watch the routesetters work or use a drone or other device for a closer view.
Is every round on-sight?
No. World series boulder rounds are all on-sight, and youth events may use flash formats in qualification.
Why the rule exists
The rule book calls climbing "a problem-solving sport" that asks for creative movement, spatial awareness and the ability to read a three-dimensional challenge. It says these skills are tested best on-sight. A climber who has watched ten others fail knows what not to try.
Where it differs
| Where | What changes | Source |
|---|---|---|
| On-sight round | No information beyond the official observation | WC Competition Rules 5.3; 5.4 |
| Flash round | Demonstration given; coaches may advise | WC Competition Rules 5.5 |
| Boulder final | Two minutes of observation for each boulder | WC Event Regulations, Annex C 4.9 |
| Boulder call zone | Arranged so that climbers cannot see boulders they have not yet tried | WC Event Regulations, Annex C 4.3 |
| Speed | The route is known and practised | WC Event Regulations, Annex B 2.1 |
From the rule book
World Climbing, Competition Rules (version 3, January 2026), Rules 5.3 to 5.5 and 13.1 with notes 11 and 12; World Climbing, Event Regulations (version 3, January 2026), Annex C section 4. Checked 14 October 2026. Official documents: World Climbing Competition Rules, January 2026 (PDF) and World Climbing Event Regulations, January 2026 (PDF).