This will likely be an opinion-based thing, but that's fine. So, you're a Rogue Trader, traveling along, and you find a world with a resource you fancy. Now, you could blast its current owners back to the Stone Age, with your weapons, and/or enslave the planet to your/the Imperium's will, but the people there seem intelligent, and interested in a partnership; you get the resource, and allies, possibly (and ones other RTs/the Imperium can't as easily influence), and they get something akin to access to the wider galaxy, possibly some of your resources. It could be a win/win.

Thing is, in a setting like 40k, once you forgo the dakka! option, I could see this accord being sealed by something like a marriage. This works, but you, the Rogue Trader, might be the wrong gender/persuasion, or already married. You might not be willing to use your hand up; who knows if another, similar situation might creep up, and you can't marry again? (a personal choice) You might not have any interest in marriage (you'll get an heir eventually, with, or without that), or you might be like Duke Leto Atreides, of Dune, and need to always keep a potential option for advancement by marriage open; this resource might be nice, but not compared to marrying the Lord Sector's grand-daughter, and cementing a truly powerful relationship. You also might not have an easily available sibling, ready to do the deed for you.

Well, you are part of a dynasty that stands akin to a Planetary Governor, or even an Inquisitor, depending on your dint, and you are not alone. You bring your retinue along, and these people might have been part of your dynasty for their entire lives, whole generations of their family, serving your family. Could it work, if they were interested, to have one of them marry the representative of the place you want to "add to your dynasty's holdings", sort of in your place? With the weird, semi-feudal world they call 40K, if you, a Rogue Trader, are important enough to basically be a Noble, could you make a case that your immediate retainers, people possibly so loyal to you, and your family, that they actually accompany you , and declared as such by you, would qualify?

I kind of like the idea that the other characters are also "pseudo-nobility", and could, in this way, add to the dynasty's web of influence, same as its scion. The RT might be a step above, mechanically-speaking, but their retainers are directly connected to the resources, and their families might be sworn to service, eternally. It could be a nice way of having them also feel inclined to branch out their personal obligations, or try to acquire things, like most people do (a spouse, a reward, whatever have you). They can access your funds, they can garner you Peers/Enemies, that effect your whole dynasty's PF. Seems they maybe could contribute in this way, too.

Could it work? Has anyone done it, and care to share? Sorry if it's a little weird, but it seems it could be a fine excuse to do some actual role-playing, maybe even a reason to, if you don't happen to be the Rogue Trader.

First and foremost: I love the idea. Anything that increases the storytelling of a RPG is in my opinion a big bonus and convoluted marriage strategies certainly fal in that category. So as far as the game goes, it should work.

Secondly, as far as the mechanics go, this depends a bit on the GM. In a classical White Wolf game, family members would rank as retainers and allies and you could allocate points to this 'resource'. In Rogue Trader you might include it in the backgrounds, to be bought with XP (at character creation). But you obviously could devise other ways of solving this practical issue. As far as I am concerned, a GM can always add disadvantages to balance out to obvious advantages. The RT's cousin would indeed be a perfect candidate for marriage, but he most definitely has his own will and ideas. For one thing is certain: family members should never be mere pawns in the game. They do have their own agenda, which can become very interesting indeed.

Finally, I do think we can categorically state that a Rogue Trader is by his very nature a 'Peer of the Realm' and as such a member of the higher Imperial nobility. We could well compare him - in medieval terms - to a duke with the unique prerogative of going beyond the borders of the Empire to expand its reach. That makes him a very eligible partner for the highest planetary and sector spanning families. Furthermore, what family would not like to have an alliance by blood to someone who can raise fleets and armies?

However, the other party members are of a different order. For starters, you can scratch the Navis Nobilite and the Astropath Transcendant. The Navis is in all likelyhood a part of his own dynasty and the marriage policy of the Navigators are a whole chapter on themselves. The Astropath stands apart from the rest of the Imperial social universe. Whatever he might have been at birth, now he is wedded to his fate. For comparable reasons, the servants of the Adeptus Mechanicus and the Adeptus Ministrorum would not makeideal marriage candidates (barring exceptions). Which leaves you with the 'normal' human retainers of the RT. Here it becomes a bit more complex.

For a lot depends on their birth. If they descend from noble blood themselves it is easy: they are noble (although possibly of a different dynasty, making things again more complex). If they were not....well, their acts and experience might have raised them to greater glory. Or they might have received a title from a rightful authority (which even could be the RT). But nothing is assured and depending on what they play, they might still not fit into civilised company, whatever renown their deeds might have garnered.

Could it work?

Why not? RT in my current campaign actively uses her relatives as local representatives of Dinasty. С ousins and second cousins / nephews/nieces - if they have skills - are better, from her POV, than some outsider. While there wasn't actual marriages to the date - if it will look as the better option, then why not?

Definitely. Stars Of Inequity has rules for generating colony governors as "one of a dynasty's seemingly infinite supply of half-brothers, cousins, nephews and nieces" - whether you install them by marriage, colonisation or bomb the place from orbit and then hand them some medical supplies and a dustpan and brush, it all works out the same in game mechanics.

I think I remember reading somewhere that other characters may also be part of the Rogue Trader's dynasty. Roles, such as, sensechel, arch militant and voidmaster (As Van Reibeek pointed out most of the others wouldn't be as likely, although not impossible) may all be cousins, brothers and/or sisters of the character that actually inherited the Warrant of Trade and this would make them ideal candidates for marriages to form alliances. Whilst missing out on the Warrant of Trade they still wield enormous political power within the dynasty.

The bonus of using player characters is also that their is more scope for role-playing the marriage proposals (But I am already in love with another, I don't want to marry her or but the Planet's Crown Prince is a total pig, you can't make me marry him or possibly even a chance at true love (how non-rpg!)). This also keeps the Rogue Trader free to wait for that perfect political match (unless he/she secrets loves the person the other PC is to marry) or even more likely continue playing the field as befits one of such power, wealth and reputation.

I haven't done it, but succession through bloodline seems like an appropriate 40K thing to do, especially since most of the time your Rogue Trader is lost in the Warp for months or years on end, so you need some reliable, trustworthy people who you can also execute for being faithless at a moment's notice.

As always, the question of "Would it work?" is always true, but in this case you could explcitily make it work for you. The lines of succession for a warrant are always unclear, what if it has to go to a non-direct family relative of the current Warrant Holder? Then you'd have a bunch of family hang-ons clamoring for position, trying to please you, and debating when is the optimal time to poison you?