What is the figure-eight knot used for?

• A. to secure a loose end
• B. to tie around an object
• C. to stop the rope end from moving through a device
• D. to anchor around a post

Answer: (C)

The figure-eight is a stopper knot. Its main purpose is to create a bulky end that won’t slip back through hardware like a belay device, carabiner, or a crack in a rope guide. Because of its shape, the rope end gets stuck at the point where the knot sits, preventing movement through those devices under load. That precise function—stopping the end from moving through a device—is what makes this knot the best choice in this context.

Other options describe related-sounding tasks, but they aren’t as specific to the knot’s primary use. Securing a loose end is a general idea, while tying around an object or anchoring around a post are tasks typically handled by other knots better suited to those exact motions.