The 2018 World Magic Cup featured two formats: Team Sealed and Team UnifiedStandard. Team Sealed is a variation of Sealed deck where the team shares a pool of twelve Booster packs, which is used to build three 40-card decks. For the Team Unified Constructed portion, like in 2017, Standard was the featured format. Team Unified Constructed means that with the exception of basic lands, there may not be any copies of the same card in two different decks. For example, only one player on a team may use Lava Coil, regardless of how many copies of the card that player has in their deck.
Day 1 - Friday, 14 December
Three rounds of Team Sealed
Up to four rounds of Team Unified Standard
Day 1 featured at most seven rounds of Swiss play; all teams that won their fourth match received byes every round for the rest of the day.
The top 32 teams at the end of the day advanced to Day 2 of competition. This essentially meant that all teams that picked up their fourth win prior to round 7 advanced, plus a few teams with 4–3 records.
Day 2 - Saturday, 15 December
Phase 1 - up to three rounds of Team Unified Standard
Phase 2 - up to three rounds of Team Unified Standard
On Day 2, teams were divided into eight groups of four teams each (Phase 1). The four teams in each group played up to three rounds of double elimination; the top two teams in each group advanced to Phase 2. For Phase 2, the sixteen remaining teams were again divided into groups of four, and they played up to three rounds of double elimination. The top two teams in each group proceeded to Day 3 of competition.
As with the 2017 World Magic Cup, draws were not allowed on Day 2. Each round lasted 60 minutes, and if time was called and there was no conclusion to the match after extra turns, the match was decided with the following tiebreakers:
The deciding match is determined by game count at the end of extra turns.
If the deciding match's game count is tied, the player with the highest life total wins the match.
If the team match count, game count, and life totals are tied at the end of extra turns, the first change in life total results in the player whose life total is higher after said change winning the match.
If the game count becomes tied in extra turns, and a third game needs to be played, the match is decided by the first change in life total, with the player whose life total is higher after said change winning the match.
Day 3 - Sunday, 16 December
Quarterfinals, semifinals and final, featuring Team Unified Standard
The top eight teams then competed in a seeded (based on total number of points from Day 1 and Day 2), single-elimination bracket.
The first day of competition featured two formats: Guilds of RavnicaTeam Sealed (3 rounds) followed by Team UnifiedStandard (up to 4 rounds). Teams played until they had four wins or seven rounds had been played, whichever came first. Teams that reached four wins before round seven were guaranteed advancement to day 2, while the teams that reached the "four wins"-threshold in round seven had to hope that their tiebreakers would be good enough to see them through. In the end, 7 teams made it through with 4–3-records, while 3 teams didn't. These were Argentina, Poland, and Croatia.
The best performers were Peru, Israel, Italy, and Hong Kong, all starting 4–0 and securing advancement at the earliest possible time.
Day 2 featured two sets of so-called pool play. Teams were divided into groups of four, and teams in each group played three rounds of Team Unified Standard double elimination. This meant that the two teams in each group that won two matches proceeded to the next stage, while the remaining two teams were eliminated.