How to Tie a Square Knot

The square knot, also called the reef knot, has been used by sailors aboard ship for centuries [source: Netknots]. It's also the knot we tie (underneath the bow) when tying our shoes. Square knots can easily slip or come undone with movement or jam under a heavy load, so never use them for holding a critical load or supporting a person [source: Animated Knots]. In fact, although for the purposes of this tutorial we will use two ropes, Rope A and Rope B, a square knot should never be used for tying two ropes together [source: Netknots].

Place two ropes in front of you horizontally, parallel to each other. Starting with Rope A in your left hand and Rope B in your right, tie a square knot as follows:

Cross the end of Rope A over the end of Rope B to form an "X."
Pull the end of Rope A under and then over Rope B. The ends of both ropes should now be pointing up, forming a "U" shape. This is the first half of your knot.
Tie another overhand knot by crossing Rope A over Rope B.
Pull Rope A around Rope B and through the space formed in step 3.
Pull on the ends of the ropes to tighten, completing the knot.
You can add extra half-knots (half-hitches) for security. But again, do not rely on these to keep your knot from coming undone.

An easy way to remember how to tie a square knot is, "right over left, left over right" [source: Troop 824].