The Jeopardy! Battle of the Decades is a special 5-week tournament airing throughout the 30th season of the syndicated game show Jeopardy! to commemorate the 30th anniversary of the Alex Trebek-version of the show. The tournament involves 45 previously successful Jeopardy! contestants split into three groups based on the time period of their initial appearance on the program.^[1] Though the groups roughly represent 1984-1993, 1994–2003, and 2004–2013, they are referred to as the 1980s, 1990s, and 2000s, respectively. The tournament's 1980s round began airing on February 3, 2014 with the tournament's final episode set to air later that year on May 16, covering 25 shows in total.^[2] The tournament's grand prize is slated to be US$1,000,000.^[1]

45 contestants participated in the Battle of the Decades, with 15 players from each "decade" the Trebek-version on Jeopardy! had been airing.^[1] Of the 45 participants, three were selected by the viewers using online polls from the show's Twitter account and official website, with the choices coming from a producer-created shortlist.^[3]

The tournament was played in four separate rounds. The first three rounds featured contestants grouped by year of their initial appearance on the show, and competing against players from the same "decade" (as defined by the program). Gameplay in this round was of the sudden death variety, with no wild cards for high-scorers among non-winners (it was "win or go home"), and only the winner of each game moving on to the final round of the tournament.

The tournament's final round will consist of the traditional two-week tournament format, with a week of quarterfinal matches between the 15 players passing through their decade's round. Each game will have one quarterfinalist from each decade. These matches will produce 9 semifinalists, consisting of the five quarterfinal winners and four wild cards for the high-scorers among non-winners, similar to Jeopardy's annual "Teen Tournament", "Teachers Tournament" and "College Championship". The winners of each semi-final game will compete in a two-day, cumulative championship match for the grand prize of $1,000,000. $100,000 is awarded to 2nd place, $50,000 for third place, $25,000 for eliminated semifinalists, $10,000 for eliminated quarterfinalists, and $5,000 for players eliminated in each prelimary round.

Contestants in the 1980s bracket of the tournament initially appeared on Jeopardy! from 1985-1993.^[4]

Contestants in the 1990s bracket of the tournament initially appeared on Jeopardy! from 1993-2002.^[4]

Contestants in the 2000s bracket of the tournament initially appeared on Jeopardy! from 2003-2012.^[4]

^1 India Cooper, Shane Whitlock and Maria Wenglinsky were selected as standby players for the quarter-finals and was part of the traveling contingent for the quarter-finals taping. In Jeopardy! tournaments, standby players usually are the next highest scoring player on eligibility lists. For this tournament, one eliminated player from the preliminary matches was chosen by producers as the standby player.
^2 Politicians and political appointees are ineligible to participate on Jeopardy! Since Richard Cordray was director of the Consumer Financial Protection Bureau at the time of taping and broadcast of the show, he was ineligible to receive the $5,000 consolation prize all invitees who lost their preliminary game received. It is unknown if the money was donated to a charity of the producer's choice (which is typical for politicians that play during Power Players Week) or forfeited. Although ineligible, Cordray's $5,000 count towards his career earnings total.
^3 This contestant did not qualify to play Final Jeopardy! because he or she had a zero score at the end of Double Jeopardy!.

• Official Jeopardy! website
• 1980s Vote
• 1990s Vote
• 2000s Vote
• Tournament of Champions Yearbook
• Battle of the Decades Bracket
• Battle of the Decades News
• 1980s Week
• 1990s Week
• 2000s Week
• Finals Week
• J! Archive - complete recaps of all BotD games