This year's 18xx event will remain as an opening weekend tournament lasting three days. 1830, 1846, 1861, 1862 and 1880 as well as four games voted in by email survey (1856, 1870, 18EU, 18NY that have been played in the past) are eligible for the tournament. The 18xx event will be held from Saturday through Monday of the opening weekend. There will be four preliminary rounds, two each on Saturday and Sunday, with a semifinal and a Final round on Monday. All games can be played in any prelim, but it is suggested that shorter games be played during the first prelim each day, and longer games during the last prelim. Emphasis will be placed on making all games 4-player whenever possible, since this will be the preferred format for the semifinal and Final. [For example, if 23 players appear for a round, with nine players for 1846 and 14 for 1830, the games will be apportioned as follows: 1846: a 4- and a 5-player game; 1830: a 4-player and two 5-player games. If eight of those 23 players want to play 1846, the division becomes 1846: two 4-player games; 1830: three 4-player and a 3-player game.] Players will be placed in games at random, except that players that have met in previous rounds will be moved where possible.
The semifinals will consist of 16 or 20 players depending on the number of heat winners who appear. Alternates will only be used to round to the next higher number if needed. If more than 20 winners appear for the semifinals, tie-breakers will be used to determine the 20 winners to advance. Players in each semifinal game will vote on which tournament eligible game to play. Once a game receives a majority of votes from the semifinal participants, it will become the designated option for that game. If the players cannot agree to play that game, they will play the default game of 1830 (classic). Voting among the finalists for the Final game will be conducted in the same way. The winners of the semifinal games will advance to a Final which will start after a short break following the last semifinal game. If necessary, semifinalist runners-up can move up (seeded by percentage of the winning total) to ensure a 4-player Final. The top finisher from each semifinal who did NOT advance to the Final will play in a consolation game at the same time as the Final to determine the remaining plaques to be awarded.
The WBC Multiple Entry-Single Elimination (MESE) seeding criteria are: 1) Most wins; 2) Win in first heat entered; 3) Win in second heat entered; 4) Win in third heat entered; 5) Win in fourth heat entered; 6) percentage of winning score; 7) average finish in all heats entered; 8) high dice roll. For all ties, criteria will be checked in order.
The time limit for all heats, the semifinal, and the Final is six hours. No stock round will begin within 30 minutes of the round conclusion unless there is unanimous player consent to finish the game. In the last 15 minutes of a round, only route running, revenue collection, and train purchases may be conducted (tile placement, tile upgrade, or token placement will not be permitted). Unless there is a player bankruptcy, rounds conclude at the end of that series of operating rounds.