Below is a list of changes that are being made for Roulette Rivals 20. This list may not be exhaustive, so it is recommended to still read over the full list of rules.
RR20 will be under the motto of approachability to the game of Hitman Roulette. One of the changes made in this name is the reduction of the available map pool from 19 to 11 maps, which can be seen below.

All other missions cannot be banned or selected during RR20. It is therefore also not necessary to own access to other locations, most importantly the DLC missions New York and Haven Island.
Due to strong community support, RR20 will not be hosted as in a Double Elimination format as orginially planned, but as a two stage tournament, consisting of a six round Elimination Swiss Stage and a Double Elimination Knockout Stage. This also means the tournament will now run from 24 July to 13 September.
In Elimination Swiss, players who win 4 matches immediately advance to the KO Stage, players who lose 3 matches are immediately eliminated. The first four rounds of Elimination Swiss are played in a First-to-5 (Ft5) format, with the last two rounds being played in a Ft7 format, which will also be the format for the KO Stage. The Grand Final will be Ft9.
The KO Stage will feature all players advanced in a semi-seeded Double Elimination bracket, with the players with the same amount of losses in the Elimination Swiss Stage being grouped together as same seeds.
Tying in with the previous changes, there will be no RNG maps in RR20. All maps in the pool will be either picked or banned by the players. This also means there will not be the usual selection restrictions based on previous matches. The exact pick and ban process for each round and the full tournament format can be found here.