Many climbing routes have grades for the technical difficulty, and in some cases for the risks, of the route. The first ascensionist can suggest a grade but it will be amended for the consensus view of subsequent ascents. While many countries with a tradition of climbing developed their own grading systems, a small number of grading systems have become internationally dominant for each type of climbing, and which has led to the standardization of grading worldwide. Over the years, grades have consistently risen in all forms of climbing, helped by improvements in climbing technique and equipment.
In free climbing (i.e. climbing rock routes with no aid), the most popular grading systems are the French numerical or sport system (e.g. 7c+), the American YDS system (e.g. 5.13a), and latterly the UIAA scale (e.g. IX+). These systems grade technical difficulty being the main focus of the lower-risk activity of sport climbing. The American system adds an R/X suffix to traditional climbing routes to reflect the additional risks of climbing protection. Notable traditional climbing systems include the British E-grade system (e.g. E4 6a).