A handfasting or handbinding is a ritual that binds two people together. It is often done as part of a wedding ceremony or as the ceremony itself, in place of a wedding or it may be a more temporary arrangement.
A handfasting is a magical contract, binding two individuals together as partners in life for a specified period of time – till death, as long as love lasts, forever, a year and a day, etc.
Although the ceremony does vary by tradition, it generally requires both individuals to be willing participants in the binding. Their hands are bound together with a cord by an officiant and words are spoken by the officiant and the two individuals sealing the spell.
The words spoken at this time generally outline the expectations of the contract, including the length of time it is to last and may take the form of wedding vows if the rite is performed in the context of a wedding ceremony.
Depending on the tradition, and perhaps the officiant, the cord may bind the hands loosely and be removed immediately after the ceremony is complete or the cord may be bound tightly and the two may remain bound through additional rites or for a specified period of time.
The cord itself varies according to tradition as well, with some traditions placing strict emphasis on colors and materials while others give no specific guidance in this area. The cord is not always a cord, per se, it may be ribbon, yarn, I have seen handcuffs used.
Although handfasting is traditionally between two people, some traditions allow for handfasting between more than two individuals. There are no gender restrictions with regard to handfasting.
Handfasting is typically done in front of witnesses, though traditions vary with regard to their number and necessity.