The gi (also called a kimono in Brazilian Portuguese) is the traditional training and competition uniform in BJJ. It consists of a heavy woven jacket, reinforced trousers, and a coloured belt indicating rank. The fabric is thick enough to withstand gripping without tearing.
Gi-specific training makes heavy use of cloth-based grips: collar grips, sleeve grips, lapel grips, and belt grips. These enable chokes, sweeps, and positional controls not available in no-gi. Many foundational techniques — bow-and-arrow choke, collar drag, loop choke — require gi fabric.
Most UK academies train both gi and no-gi. Beginners are usually advised to start with the gi, as the slower pace and extra friction make it easier to learn positional concepts. IBJJF and most major competition formats have gi and no-gi divisions.