The term "'''backup knot'''" (or "safety knot") describes any secondary knot that is used to make a primary knot more secure.

Backup knots function in two possible ways.  A backup knot can prevent the [[working end]] from slipping into the primary knot, allowing the primary knot to unravel.  The backup knot can also serve as a redundant knot, capable of independently supporting the load, in case human error caused the primary knot to be tied or dressed incorrectly.

A backup knot is often used when someone's life is at stake, such as climbing and technical rescue.  It is also used when the rope material is particularly slippery, or when the primary knot is prone to slipping under certain circumstances (heavy loads, multiple load/unload cycles).

Backup knots are often tied around the standing part of the rope, particularly when used for safety-of-life purposes.

[[Category:Terminology]]