Type
The first step in setting up your sack race is to decide whether you intend to have a solo or three-legged race. In a solo race, each contestant runs to the bag, jumps in with both legs and hops toward the finish. In a three-legged race, each member of the two-person team inserts one leg into the bag and together they race to the finish. You can plan to do both variations or focus on one. Be sure to get enough bags for your guests. Traditionally, burlap potato sacks are used for sack races.
Set-Up
Since sack races are more of an informal outdoor game as opposed to an official sport, you don't have to get too technical when it comes to measurements. The Griffith Bag Company, a manufacturer of burlap sacks popular in sack races, suggests having the finish line 20 to 30 feet from the start. For an individual sack race, contestants begin by running to the bags, which are laid out about five or 10 feet in front of them. For a three-legged race, contestants begin in the sack and race to the finish from there. Pick a level location for your race--hopping around in a sack is difficult enough--and tie down a piece of ribbon to serve as a finish line. After one race, if the sack racers decide the finish line is too close or far away, you could simply adjust for the next race. Bear in mind that the point is to have a good time, so feel free to adjust the rules, particularly when small children are involved.
Officiating
Some of the basic rules of solo sack races are that contestants must keep both legs in the bag at all times when racing toward the finish line. They also need to have at least one hand on the bag and should hold it around waist level or higher; the bag should not fall down below the knees. To officiate, have a "referee" watch over the match to make sure everyone is abiding by the rules. The ref could sport a whistle to signal the beginning of the race and to use for "fouls" or "disqualifications." When dealing with young children, a friendly reminder might be a better course of action than a whistle. Another official should stand even with the finish line to judge the winner--just in case there is a close "photo finish."
Variations
One of the best parts about the sack race is that there are many variations and you can put your own spin on the game. One popular version is the relay race, in which contestants sack-hop to or around a given obstacle and then tag the next person in line until each member of the team has completed the race. The team whose members finish first wins. You could also add obstacle courses, prizes and other tweaks to make the race more fun for your group. Encourage participant input and let everyone have a good time with it.