The tournament was a knock-out format, with the exception that there was a provision for the two semi-final losers to play off for third place if necessary (see #Candidates qualification).
Matches consist of two regular time limit games (except for the final, and playoff for third if required, which consist of four regular time limit games). For these two games, players have 90 minutes for the first 40 moves followed by 30 minutes for the rest of the game, with an increment of 30 seconds per move from the start of the game.
If a match is tied after the regular games, tie breaks will be played the next day. The format for the tie breaks is as follows:
If the score is tied after two rapid games, further two rapid games (10 minutes plus 10 seconds increment) are played.
If the score is tied after four rapid games, the opponents play two blitz games (five minutes plus three seconds increment).
If the score is tied after a pair of blitz games, an armageddon game (in which a draw counts as a win for Black) is played. White has 5 minutes and Black has 4 minutes, with an increment of 3 seconds/move starting from move 61.
However Magnus Carlsen (world champion) and Sergey Karjakin (already seeded to the Candidates) had no need for qualification, and both participated in the tournament (even though it is highly unusual for the defending champion to do so). So the rules were actually that the top two finishers other than Carlsen and Karjakin would qualify for the Candidates. This meant there was provision for a match for third place, between the two semi-final losers, if necessary.
As it turned out, both Carlsen and Karjakin were eliminated in the first three rounds, so the two Candidates qualifiers were simply the two finalists: Armenia's Levon Aronian and China's Ding Liren.
Each of the first six rounds takes three days: one day each for the two regular time limit games, then a third day for tie breaks, if required. The final round has four days of regular time limit games, then a fifth day for tie breaks, if required.
Round 1: September 3–5
Round 2: September 6–8
Round 3: September 9–11
Round 4: September 12–14
Round 5: September 15–17
Rest day: September 18
Round 6: September 19–21
Rest day: September 22
Final (and play-off for third place if required): September 23–27
Shortly before the third-round game between Anton Kovalyov and Maxim Rodshtein was due to start, Kovalyov was questioned by the arbiter about the knee-length Bermuda shorts he was wearing, the same pair he wore in the first two rounds. Tournament organizer Zurab Azmaiparashvili then approached Kovalyov, stating that his attire violated the FIDE dress code and that he would be punished financially if he did not change what he was wearing. Kovalyov explained that he also wore shorts in the 2015 World Cup without incident, but Azmaiparashvili objected and said that Kovalyov's clothing made him "look like a gypsy." Kovalyov interpreted this as a racial slur. Kovalyov then left the tournament hall and did not return, thus forfeiting the game. He also checked out of his hotel and booked a flight for Dallas, where he is studying for a master's degree in Computer Science technology at the University of Texas. The Chess Federation of Canada filed a formal complaint about the incident. FIDE issued a report on the incident on October 1.
^The Women's World Champion, Tan Zhongyi, renounced her participation and, in accordance with the regulations, she was replaced from the average rating list.
^ abIn the 2017 US Zonal, which normally awards five spots for the World Cup, only three players, other than those who already qualified with the previous criteria, attained the required score of 50% or better. In accordance with the World Cup regulations, the two unused positions at the US Zonal Championship passed on to the American Continental Championship.