Slacklining is a balance sport which utilizes nylon webbing stretched tight between two anchor points. Slacklining is distinct from tightrope walking in that the line is not held rigidly taut; it is instead dynamic, stretching and bouncing like a large rubber band. The line's tension can be adjusted to suit the user and different types of dynamic webbing can be used to achieve a variety of feats. The line itself is flat, due to the nature of webbing, thus keeping the slacker's footing from rolling as would be the case with an ordinary rope. The dynamic nature of the line allows for impressive tricks and stunts.

While rope walking has been around in one manner or another for thousands of years, the origins of modern day slacklining are generally attributed to a pair of rock climbers living in Yosemite Valley, California, in the early 1980s. Adam Grosowsky and Jeff Ellington started their walking on loose chains and cables alongside parking lots, and over time progressed to stringing up their climbing webbing and walking it. The sport blossomed from there among climbers in the valley, and then branched out elsewhere all over the world. There are many online forums to look for more info on the history of slacklining.