Hangings seem to be a common element of westerns, so I thought I'd come up with some simple rules for Six-Shooters & Wagons.
Once a person is hung they take 5 points of damage every round until they die of asphyxiation.
It is possible to save someone by shooting through a noose. For this purpose the noose is considered to have an AC of 4 .
Gallows making hanging even more deadly. Characters dropped from a gallows must make a saving throw or die of broken neck. After this they start taking damage as above.