Transport Union Edition is out!

Yesterday (18 Dec 2025) we saw the release of The Expanse Transport Union Edition PDF rulebook (DTRPG | Green Ronin Store). This has been a long awaited release, and the expectations to the subsequent releases of the Crew Companion, Free Navy Conflict, and Daemon’s Gambit, are – speaking for myself – high.

This edition is primarily two things:

1. An update of the default assumed starting point on timeline. Where the first rulebook assumed a starting point just after Leviathan Wakes, this is edition assumes that stories will be set during the three decades between Babylon’s Ashes and Persepolis Rising. Of course, like with the first edition, there is nothing stopping you from running a game anywhere on the timeline. Substantially, it means that the book contains a lot more information from the six first books in the series, while looking towards the future Laconian invasion.
2. Calling this a new “edition” is a slight misnomer as the rules are the same. However, they have been updated and streamlined in some areas. How native gravity works has been clarified, more clarifications on gear and equipment, new gear, weapons, and armor, an updated list of ships, their armaments, new qualities (some moved over from Ships of the Expanse), updated ship combat rules so the core book is in line with SotE), and rules for agumentaion/cybernetics have been added.

The book is about 32 pages longer, and contains no foreword and no continuation of The Last Flight of the Cassandra. Not that I expected that. There is no adventure included in the book either. This means that there is more than 32 new pages of game content.

All in all the updates are significant when it comes to the rules and game options. The new clarifications are great and there is still sufficient leeway or vagueness to let you make your own decisions and interpretations for your own games. I would prefer some more precision at times, but I also appreciate the space left for house-ruling and on the fly decision-making. It has also inspired some new alternative house rules for origin and gravity (watch this space).

The updated art is also great and really showcases the diversity of the kinds of stories that can be played in the Expanse. It really feels like an update and brings the Expanse RPG universe its own look and feel! While the TV show has established a design, and the previous rulebook and supplements have built an alternative design language and look that suits the world well, this updated rulebook really improves on that previous work.

In the case of lore and setting information, the book has about 50 pages packed with information from Future History through the Sol planets, to beyond the ring, and another 20 pages for building your own Expanse series. Add in pages from Game Mastering and inspiration from Threats, and you have lots to pack onto your story, whether its Laconian agents, protomolecule experiments, colonisation, politicking, or mercenary orientated series.

The updated rulebook is a definite improvement on numerous aspects of the previous rulebook. It draws on previous supplements, but doesn’t replace them – they are still very much useful and important to flesh out the kind of campaign you want to play.