Slalom is an alpine skiing and alpine snowboarding discipline, involving skiing between poles (gates) spaced much closer together than in Giant Slalom, Super-G or Downhill, thereby causing quicker and shorter turns. Slalom skiing may also refer waterskiing with only one ski. Similar to the alpine version, the skier must pass around buoys on either side of the tow boat.
The word "Slalom" is from the Morgedal/Seljord dialect of Norwegian slalåm: "sla," meaning slightly inclining hillside, and "låm," meaning track after skis. The inventors of modern skiing classified their trails according to their difficulty. Slalåm was a trail used in Telemark by boys and girls not yet able to try themselves on the more challenging runs. Ufsilåm was a trail with one obstacle (ufse) like a jump, a fence, a difficult turn, a gorge, a cliff (often more than 10 meters high) and more. Uvyrdslåm was a trail with several obstacles.
Proper definition 
A course is constructed by laying out a series of gates. Gates are formed by alternating pairs of red and blue poles. The skier must pass between the two poles forming the gate. (Strictly speaking, the tips of both skis and the skier's feet must pass between the poles.) A course has 55 to 75 gates for men and 40 to 60 gates for women.
For slalom the vertical offset between gates is around 9 meters (30 feet) and the horizontal offset around 2 metres (6.5 feet), although these figures have changed in recent times because of significant technical developments in ski equipment (namely, increased sidecut) that have revolutionized the sport. The gates are arranged in a variety of different configurations to challenge the competitor, including delay gates and vertical combinations known as hairpins and flushes. A hairpin is a series of gates including two gates with one closing gate. A flush is a series of gates including three or more gates with one closing gate. The worldwide governing body, FIS (Federation Internationale de Ski) has a set of regulations detailing what configurations are allowed or mandated for an official course.
Because the offsets are relatively small in slalom, skiers take a fairly direct line and often knock the poles out of the way as they pass, which is known as blocking. (The main blocking technique in modern slalom is cross-blocking, in which the skier takes such a tight line and angulates so strongly that he or she is able to block the gate with the outside hand.) In modern slalom, a variety of protective equipment is used such as shin pads, hand guards, helmets and face guards.
For those who live in a warmer climate, slalom skiing is defined as water skiing with only one ski through a course very similar to the downhill skiing version. The boat drives through the middle buoys while the skiier cuts through the water from side to side, rounding a buoy on each pass.
The rules for the modern slalom were developed by Sir Arnold Lunn in 1922 for the British National Ski Championships, tried by the FIS in 1928, and adopted for the 1936 Winter Olympics. Under his rules, the gates were marked by pairs of flags rather than single ones, were arranged so that the racers had to use a variety of turn lengths to negotiate them, and scoring was on the basis of time alone, not time and style.
Innovation and rule changes 
In the early 1980s, bamboo poles (also called "gates") were replaced by hard plastic poles, hinged at the base and invented in 1979 by Peter Laehy and Stefan Dag of Aspen based rapidgate, inc. The rigid nature of the old-style bamboo gates had forced skiers to maneuver their entire body around each gate, while the hinged gates require only that the skis and boots of the skier (as the FIS rules state) go around each gate. The new gates allowed skiers to take a much more direct path down a slalom course through the process of "cross-blocking" or "shinning" the gates. Cross-blocking is a technique in which a skier's legs go around the gate with their upper body inclined toward, or even across, the gate; in this case the skier's outside pole and their shinguards hit the gate, knocking it down and out of the way. In the early 1990s, flags were removed completely from slalom gates in international competition.
With the innovation of "shaped" skis around the turn of the 21st century, equipment used for slalom in international competition changed drastically. World Cup skiers commonly skied on slalom skis at a length of 203-207 centimeters in the 1980s and 1990s but by the 2002 Winter Olympics in Salt Lake City, the majority of competitors were using skis measuring 160 cm or less.
The downside of the shorter skis was that athletes found that recoveries were more difficult with a smaller platform underfoot. Over concern for the safety of athletes, the FIS began to set minimum ski lengths for international slalom competition. The minimum was initially set at 155 cm for men and 150 cm for women, but was increased to 165 cm for men and 155 cm for women for the 2003-2004 season.
American Bode Miller hastened the shift to the shorter, more radical sidecut skis when he achieved unexpected success after becoming the first Junior Olympic athlete to adopt the equipment in giant slalom and super G in 1996. A few years later, the technology was adapted to slalom skis as well.
See also 
- List of Olympic medalists in men's slalom
- List of Olympic medalists in women's slalom
- List of Paralympic medalists in men's slalom
- List of Paralympic medalists in women's slalom
- List of World Champions in slalom
- Super G
- Giant Slalom
- Alpine skiing combined
- U.S. Ski and Snowboard Association - National governing body for Olympic skiing and snowboarding in the United States