The Hunger Games is a major source of gambling and produce intense betting, both in the Capitol and the districts. Katniss mentions people from District 12 betting on the two tributes reaped, and that "odds are given on their ages, whether they're Seam or merchant, and if they will break down and weep." In the Capitol, betting takes place throughout the Games, starting before training and increasing in intensity until a victor is determined. Various statistics are tracked and reported to help people place their bets, such as each tribute's list of kills. Some people close to the Games, such as head stylists and presumably Gamemakers as well, aren't allowed to bet. Cinna mentions that he's not allowed to bet, but if he could, he'd put all his money on Katniss.
74th Hunger Games
Betting plays a role in how the tributes conduct themselves. Katniss tries to appear strong in the arena, because "who's going to bet on a tribute who keeps sniveling over the deaths of her opponents." Katniss thinks to herself how "one of the heaviest days of betting is the opening, when the initial casualties come in". However that doesn't compare to when the betting gets really hot in the Capitol after the final eight, when they do family interviews. Peeta, when realizing Katniss intends to go to the feast in spite of her telling him otherwise, tells her to never bet at cards, as "you'll lose your last coin."
Betting Odds in Movie
The movie gives examples of betting on the Hunger Games, showing wager stations and the odds of each tribute to win. One odds board pictured was titled "Morning Line Odds," a term based on horse racing. Odds are continually updated over time, where the odds for a tribute can be seen increasing or decreasing. Training scores are important because they give the audience a starting point for betting that will continue throughout the Games. The odds listed for each tribute 3 days and 16 hours before the Games began (multiple numbers indicate changes seen during the film) were:
|1||Marvel: 5-1||17||Glimmer: 7-1||17|
|2||Cato: 3-1||18||Clove: 5-1||15|
|11||Thresh: 10-1, 11-1, 8-1||18||Rue: 60-1, 7-1||12|
|12||Peeta Mellark: 23-1||16||Katniss: 23-1||16|
Katniss and Peeta were given very low odds at first, presumably because they're from District 12 which rarely does well. Rue's odds were originally a very low 60-1, however they soon increased to 7-1. The District 8 male had high odds of 3-1, tied for the highest with Cato. The District 3 female ended with the lowest odds of winning in the film.