The Hangman's Noose is a knot used for centuries to hang people. It is suited to the job because, when tied properly, it is very secure and tightens freely, minimizing the suffering of the victim.

To tie the knot, make a bight (a loop) near on end of the rope:

______________
|______________`\
\ |
___________________________/ |
___________________________./

Double back the running end:

_____________
/'_____________|
| /
| \______________
\.______________`\
\ |
___________________________/ |
___________________________./

Wrap it around the standing end eight times. (Not all shown here).

/''\
_______/_/\ \__
/'__________| |  \
| /     | |  | | \ \
| \_____|_|__| |__\ \_
\.__________| |__| |_`\
_   | |  | |  | | \ |
________|_|__|_|__| |__| |_/ |
__________________| |__/ /_./
\ \._\_\_/ / / /
\________/_/ /
\.___./

Thread the running end through the bight you made by doubling back and tighten the turns:

_
| |     /''\
| |____/_/\ \__
/'| |_______| |  \
| /| |  | |  | | \ \
| \|_|__|_|__| |__\ \_
\.__________| |__| |_`\=======> PULL
| |  | |  | |  | | \ |
________|_|__|_|__| |__| |_/ |
__________________| |__/ /_./
\ \._\_\_/ / / /
\________/_/ /
\.___./

The number of times the running end should be wrapped round is a matter of some controversy. Various urban legends claim that it should be nine times, so that even if the man has as many lives as a cat, there is a turn for every one, or alternatively there should be thirteen turns, as obviously, being hanged is pretty unlucky. However, Clifford W. Ashley, in The Ashley Book of Knots, recommends eight turns, as that offers the best balance between free running and keeping a sturdy structure to the knot.

In fact, a strict protocol and a lot of tradition are attached to this knot, how to tie it and how to use it. When a sailor was hanged, the boatswain was responsible for setting up the lines, and it was a point of honour for the equipment to work correctly. Ashley describes how a modified sheepshank knot was used to hold the slack rope, which could be spilled by pulling out a wooden block, releasing exactly six feet of rope. He also suggests that the knot should fit snugly and be placed behind the left ear of the subject. This ensures that the neck is broken cleanly, rather than the subject being asphyxiated.