Multi-pitch routes are also graded using the YDS.
Ice climbing allows adventure seekers to scale up frozen waterfalls. On vertical routes, climbers sink ice tools and crampons into the ice to ascend. Natural features and ice screws are used for protection on lead, but lead climbing on ice can be potentially more dangerous than on rock. Although some of the movement principles of rock climbing carry over, ice climbing is a very different beast. Ice climbs are graded using the WI scale based on the steepness of the ice and range in difficulty from WI1 to WI6.
Ice routes can sometimes present a mixture of ice and rock. In this case, climbers use dry tooling techniques, where they place their ice tools into cracks and crevices in the rock in order to climb up.
Free soloing is the highest consequence form of rock climbing. Free solo climbers climb routes that are usually free climbed with equipment, but without the use of ropes. In this way, free soloers are alone on the wall, only requiring their shoes and chalk.
A very small proportion of elite climbers engage in free solo climbing. Falls when free soloing are deadly, with only the odd exception.