A very good article on nobles of the Imperium is in Travellers' Digest
Number 9, the oh-hell-somebody-just-shot-the-Emperor issue announcing
the birth of MegaTraveller. However, if you don't have that one, I can
answer your questions with a reasonable degree of authority.
<pause as Metlay dons his Historian hat>
Based on how the GDW/DGP Traveller universe works, Dominic, you blew it
bigtime when you let two characters roll up random dukes and duchesses.
On the IMperial noble rankings, the ducal seat is the highest to which
anyone can ever hope to aspire without assassinating the Emperor! A duke
not only has Imperial powers of fleet command and revenue from planets
under his sphere of influence, but also owns fiefdoms of his own that
his household administers directly. The same is true of other nobles,
but the difference where a duke is concerned is SCALE: a duke has direct
control over anywhere from two to six entire PLANETS as personal fiefdoms
(read: as far as the Emperor is concerned, those worlds are the duke's
personal property), and administrative power over an entire SECTOR! That's
sixteen subsectors, and usually hundreds of planets, that need to be
administered. And administered DIRECTLY, not through a bureaucracy.
A duke can take vacations for brief periods on his own fief-worlds, or
extended ones due to health reasons, but not without causing some measure
of concern on the part of his government officials. He will NEVER leave
his sector of power unless on extremely important affairs of state, for
example to visit the Emperor for some reason or another, and he leaves his
power base for as little time away as possible. He will NEVER travel
incognito unless his life and future are on the line (Norris retrieving
the vital document he needed in the 5FW), and on any other occasion his
travels are widely publicized and treated with HUGE fanfare-- he will
have no more chance of a quiet trip than an American President would.
He has effectively infinite wealth and infinite resources to call upon,
up to and including entire Naval fleets and entire planetary treasuries.
If he DOES join a party, each and every adventure must revolve around him
and only him, and the party will essentially be part of his huge retinue.
There are only a few dozen dukes in the entire Imperium, if that many,
and each and every one is known by name by every schoolchild in the state.
The oligharchic nature of the Imperium makes nobles of the higher ranks
especially revered, and that means a duke will be well-known and received
in pomp wherever he goes. Period.
Oh, and I assume the duchess is the duke's wife? Two of them in the same
room would never happen except on state visits to Capital, otherwise;
that means that one or the other spouse is actually a consort, and enjoys
a lot of the privileges but little of the actual power. Two dukes of two
sectors adventuring together as part of a party is utter ridiculousness.
ONE is too, but two basically brands the adventure as impossible....
My advice is that you scale the characters back to an absolute maximum
of Social 13, and maybe only 12. Most barons have a fair amount of power
of their own, and receive good treatment when they travel, but administer
only sections of worlds (or entire, small worlds) and have little clout
beyond their systems. A marquis would have some power and influence over
a subsector or two-- that's often fifty worlds-- as well as having an
entire world as a fiefdom, and by that level, his movements are newsworthy
and he is an unsuitable party member. I find that if the players treat the
nobles as they should, any noble over rank 12 utterly trashes game
balance. Good luck!
metlay