A bachelor party (United States, South Africa), also known as a stag party or stag night or stag do (UK, Ireland, Canada and New Zealand), bull's party (South Africa) or buck's party, or buck's night (Australia) is a party held for a bachelor shortly before he enters marriage, to make the most of his final opportunity to engage in activities a new partner might not approve of, or merely to spend time bonding with his male friends (often in his wedding party afterwards).
The history of bachelor party is thought to have originated with a bachelor dinner that was traditional in ancient Sparta (5th century BC) where soldiers would toast each other on the eve of a friend’s wedding.
A bachelor party may involve activities beyond the usual party and social gathering ingredients (often drinking alcohol and gambling), such as going to a strip club, hiring a stripper or escort, and in some traditions more hazing-like tests and pranks at the future groom's expense, which shows the whole thing is also a rite of passage from bachelorhood (associated with an adolescent lifestyle, often in the common past of most participants, e.g. in their student years) to "more responsible" marital life.
The task of organizing a bachelor party is often traditionally assigned to a male sibling of the bachelor or to the best man. Otherwise, any (close and/or reputedly party-minded) male friend will organize it. The planned activities of a bachelor party are traditionally kept secret from the groom.
Bachelor parties have also been the subject of many movies, especially comedies.
A tame version is the so-called Stag and Doe party, in which both the bride and groom attend.
In the UK, stag weekend trips are becoming mini-holidays with the groups taking part in various day time activities as well as the expected night out on the town. Popular UK destinations include Blackpool, Brighton, Bournemouth, Sunderland, Liverpool and Edinburgh. With the rise of budget airlines, there is now a growing trend for stags to go abroad , with Krakow, Dublin and Riga topping the list, followed by Prague, Vilnius, Amsterdam, Bratislava and Antwerpen.
Groups of friends attending weekends away in the UK and even into Europe with their best friend leave home on a Friday and embrace 2 days of fun. The groom who normally is called "the Stag" will have a selection of tasks to complete on the stag weekend. Group activities include paintball, kart racing and clay pigeon shooting.
Bachelor parties in the US often entail the mass consumption of alcohol, the hiring of a stripper or prostitute, and general rowdiness toward which the bride might not have a positive reaction (especially since women are not supposed to be among the invitees). Increasingly, bachelor parties have come to symbolize the last time when the groom is truly "free" and without the influence of his new wife.