Our story

Splintered Rock is a roleplaying environment - and just as our characters were not in Frank Herbert's books, so his characters are not in ours. And since we're not here simply to replay the Dune novels, but to create our own stories, some of the history has been adjusted to make roleplaying possible, and some has developed organically as our characters have affected the politics of the universe.
So, to restate: the first difference is There is no Baron Vladimir or Duke Leto or any other of the character named in Dune - there's a Duke Atreides and Baron Harkonnen, but they have different names and different character traits. The basic political and economic setup of the Dune Universe is the same, but the individuals are not.

The Governorate of Arrakis

Frank Herbert's Dune began with the departure of the Harkonnens from Arrakis. Our history is a very different one, and began with the arrival of the Harkonnen and the Atreides Houses, both having been invited to mine spice simultaneously; a License and Maintenance Charter for operating on Splintered Rock has traditionally been administered by another House, allowing limited spice mining activity in return for repair work, and has recently passed from House Rabban to House Bayezid, another House Minor. So the second difference: The Harkonnen and Atreides control Arrakis jointly, and they are both recent arrivals; House Bayezid also operates on Splintered Rock only.

The Bene Gesserit Breeding Programme

The Bene Gesserit breeding programme is not at the same stage as in Dune. Don't assume their goals are the same, or their methods. And in particular, There is no Kwisatz Haderach; maybe the Sisterhood is aiming for one someday, but that day is not today or in the near future, and if it was, it wouldn't be widely known at all.

Location

This isn't so much a difference in fact as a difference in emphasis. Roleplay mostly happens on Splintered Rock, an outpost in the desert, not the city of Arrakeen or the palace of the Emperor on Kaitain. We've got desert space, and we're looking to expand it, and the lack of SL space outside of Splintered Rock doesn't mean we can't have episodes that take place outside it - notionally, at least.

Recent History

Splintered Rock's position in time has sometimes been defined as 'twenty years before Dune'. It's a useful way of thinking about the technological level, but it can lead to misunderstandings, when people try to fit us in with events in the books by Brian Herbert and Kevin J Anderson - and find it doesn't work. This means don't rely on the prequels, either. We've deviated from Frank Herbert's timeline, the same goes for his son's work.

Similarities

Although we've diverged from the Dune books in places as a result of the medium, we want at the same time to keep true to the atmosphere of the novels.

Many things remain Mysterious

This is a whole set of 'things to remember'. Many things are revealed to us as readers and to the characters as participants over the course of the Dune books that simply weren't common knowledge - and were well outside the realms of many experts - before the beginning of the first book. These include:

• The worm/spice relationship.
• The amount of water on Arrakis.
• The Tleilaxu Masters and their role in its society.
• The location of the Ixian homeworld.
• The Bene Gesserit breeding programme and the concept of the Kwisatz Haderach.

Technology

In the same vein, a number of technologies in the Dune universe had not been developed by our time - generally speaking, anything that appears in novels published after the original Dune. So we have shields, lasguns, suspensors, ornithopters, and the guild has foldspace technology. But no-ships and no-rooms are a closely-guarded secret if they even exist, and the advanced biological techniques mentioned in the later books.

Ancient History

The Great Convention, the Orange Catholic Bible, the Zensunni Wanderers, Holtzmann technology, all the old histories and institutions exist just in our universe. As in the original Dune, they're shrouded somewhat in fable, and we prefer to keep it that way officially, and leave the rest to your personal preference or imagination.