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The Master Builder Series, or MBS, is a subtheme for Star Wars that was introduced to distinguish some sets from the Ultimate Collector's Series line.



75222 Betrayal at Cloud City, the first official set from the Master Builder Series line.

The Master Builder Series sets were officially introduced in 2018, along with the controversial release of 75222 Betrayal at Cloud City. Although there were no explicit mention of the subtheme in the box, the official description mentioned: This is a description taken from Please do not modify it. (visit this item's product page)

This amazing set is part of the LEGO® Star Wars Master Builder Series.

MBS sets are Direct to Consumer (D2C or DTC) sets, which are usually sold in LEGO Shop or LEGO Stores only and hard to find elsewhere. It is a common point they share with the UCS line. They also include a very wide range of minifigures: currently, the only two MBS sets, 75222 Betrayal at Cloud City and 75290 Mos Eisley Cantina, include both 20 and 21 minifigures. They have a wide interior that adds playability, along with some smaller ships or creatures that provide an extra addition to the main building.

If 75222 does not include a logo for Master Builder Series, 75290 adds this one for the first time.

As there are two big D2C sets for the Star Wars theme that release every year, there are no regular release dates for MBS sets currently: both sets were released in October 2018 and 2020. In October 2019, an UCS set released instead, 75252 Imperial Star Destroyer. It can be guessed that MBS sets can only release in either May or October, when the D2C Star Wars sets release every year since 2016.

Controversy over past sets and definition[]

The introduction of MBS sets was surprising for many fans, as this set could be considered as part of the Ultimate Collector Series line since it was a remake of 10123 Cloud City, which is included in the UCS Promotional Poster. Plus, many similar sets, scaled to minifigures and with large interiors were already released under the UCS tag, such as 75098 Assault on Hoth or 75159 Death Star that both released in 2016, only two years before 75222's release. It was the same year that controversy over 75098 also emerged, as this set was more seen as a collection from different Hoth sets rather than an UCS set. Following that controversy, it is likely that LEGO decided to introduce the Master Builder Series to make a separate line from UCS and to end such discussions.

A few days after 75222 was officially announced, LEGO clarified the nature of this MBS series for the future, to make a clear distinction between MBS and UCS:

The Master Builder Series models are large playsets and beside being complex builds they are characterized by having many play features and functions, interior details as well as a range of minifigures.

Ultimate Collectors Series will remain highly detailed display models providing complex builds with a focus on authenticity and both Ultimate Collectors Series and Master Builder Series will continue as a way to highlight the unique characteristic of each style of model.

Many previous sets fall under that definition of large playsets and (...) complex builds they are characterized by having many play features and functions, interior details as well as a range of minifigures, including lots of sets which were labelled under the UCS line: 10123 Cloud City, 10131 TIE Fighter Collection, 10144 Sandcrawler, 10178 Motorized Walking AT-AT, 10188 Death Star, 10195 Republic Dropship with AT-OT, 10236 Ewok Village, 75059 Sandcrawler, 75098 Assault on Hoth and 75159 Death Star all fit this description. As the LEGO Group never published a complete list of MBS sets, this description is not seen as retroactive and is usually not considered for any set which were released before 2018.

75244 Tantive IV, that could fall under that definition of a large playset, having a complex build and a few minifigures, is not a part of the MBS series, despite not being a part of the UCS line either. This also led to controversy, as MBS seemed to be a tag that only applied to the somewhat different nature of 75222, while the line would go on two years after the release of the first set.

List of sets[]

Image#SetNumber of piecesMinifiguresPriceRelease
75222Box75222Betrayal at Cloud City2812Bespin Guard (x2), Boba Fett, C-3PO, Chewbacca, Cloud Car Pilot (x2), Darth Vader, Han Solo, Lando Calrissian, Lobot, Luke Skywalker, Princess Leia Organa, Stormtrooper (2), R2-D2, Ugnaught, IG-88$349.99 / €349.99October 1, 2018
75290 alt175290Mos Eisley Cantina3187Luke Skywalker, Obi-Wan Kenobi, Han Solo, Chewbacca, R2-D2, C-3PO, Greedo, Ponda Baba, Cornelius Evazan, Wuher, Garindan ezz Zavor, Jawa, Sandtrooper x2, Bith x3, Kabe, Momaw Nadon, Kardue’sai’Malloc, Hrchek Kal Fas$349.99 / €341.17September 16, 2020


  1. According to Hoth Bricks' report on official communication about Master Builder Series, published on August 30th, 2018 on this blog article (in French, communication in English).