At the moment I'm running Forsaken Bounty as an introductory adventure for my player's campaign. When that's finished, I intend to turn the game's control over to the players and make it something of a sandbox mode game, where they go and do whatever they want and I merely fill in the details as they explore them. Now and then I intend to give them hooks which will bring into GM-driven plotlines, but for the most part I envision it as being largely player driven.

This prompts my question. What is the best way to handle open ended exploration? Once they're done with their business at the Battleground, should I present them with a list of nearby star systems and then have them choose one or several to explore? Being right at the opening of the Maw you'd suppose these would largely be subject to claims already by other Rogue Traders.

What methods do you use when your players are exploring the Koronus Expanse on their own, without a specific objective? How do you get things started?

Nothing, eh? Not a single comment?

What I do, is have any number of rumours available upon return to a major Port. Stuff like "House Winterscale has sent a large amount of specialist mining equipment through the Maw." "There are rumours that the Astropathica has lost contact with the Prison planet Darac" "Drunken crew from the Rogue Trader vessel 'Golden Future' have been bragging about their Captain uncovering an ancient digsite" "Astromancers have spotted faint stars in the Unbeholden Reaches, almost completely obscured by dust clouds. No logs of anyone visiting these systems have been found so far" "The planet Zida III has sent out a distress signal, asking for para-military support, and promising great wealth to those who respond quickly"

I do this at the end of a session, often with only the faintest outline of what I would have happen adventure wise if they'd get there. It's usually pretty clear which story they find most valuable, and during the week I flesh it out more.

I think the best way to prepare a sandbox game is to create a "living social system" of interacting NPS-persons and -groups. Your players should be able to choose with whom they want to ally and what they want to achieve – but all of their actions should influence that social system and should trigger reactions from other members of that social system.

In a Rogue Trader game, the members of that big social system could be other Rogue Trader dynasties, governors, smugglers/pirates, ambassadors of xenos-races, crew members of your Rogue Trader's ship and so on. And of course, it is very helpfull to provide a well-elaborated home-system (in which your Rogue Trader owns some infrastructure which is essential for him.)

As soon as you have elaborated such a living social system, you can throw in some plot hooks and just watch what's happening.

(By the way, dynasties are perfect for the concern of a sandbox-game: If your players kill some crucial NPCs, those "NPC-types" aren't lost for the campaign: You can "reproduce" them by introducing their descendants. You can be damned sure that whenever someone important and powerful vanishs, there will be another one who takes his place.)

Oh, and don't forget: Sandbox games will require more effort from the GM than most linear games, especially in matters of preparing a solid background-setting. Linear games are by far easier to arrange – however, I would never want "to go back" to linear games once I tasted sandbox-RPGs.

At last, keep in mind that there are some kinds of players who don't get along with sandbox-games. They are overwhelmed by the amount of freedom and don't know what they "should do". These kinds of players need some leading plot-offerings they can follow, so you should have some pre-set "storylines" up your sleeves.

I'm pretty good at creating a social landscape for sandbox-style games, but my problem is a Rogue Trader-specific one; coming up with a starchart for the players to explore. How many star systems do I offer? In my game, they're just now entering the Expanse from the Maw. Just how many noteworthy star systems should I provide them with? How much is too much? How little is too little?

My own campaign is based on only one star system that is really good fleshed out. I think one really elaborate star system is better than lots of thin "wishy-washy"-systems. Of course my players are leaving that star system from times to times, but the greater part of the story takes place in this system.

I think the key for such a centrical star system (or maybe two or three of them) is to create profound interactions and relations between its planets and groups. Don't create insulated worlds that are self-sustaining and isolated from the others: They simply won't bind your players to the momentum of a sandbox game (e.g. political struggle). So always create strong relations and dependencies between the planets and between the star systems.

(Maybe there is one agriworld all other worlds are dependent on. In contrary, this agriworld is dependent on militarical support because every pirate in the whole system is raiding for its transporter-class-ships. However, if one world would grant this militarical support, all other worlds would complain because they fear a monopoly. So there is an association that has build up just to allocate the rights and duties of escorts and so on... Now what will happen if an "adjacant" star system loses its food supply and wants to start trade with exactly that centrical agriworld? Maybe they have the better offers, but they will need interstellar transport-ships (instead of interplanetary transport ships) and they are far away, so they will need more time to send support to their new ally if aggravate incidents will happen...)

Take care that all your plot hooks are somehow connected to that "home system" – even if they take place in another system.

As long as your central star systems offers your players enough interesting storylines (and resources for profit, of course), there will be no need to focus too much on other systems. In my group, this one system works great as reference center for the players and until now, there was no need to flesh out many other systems.

Of course, only one system might seem to be a bit wee – after all we're playing Rogue Trader. So you could create two or three of them, but you should do it in the same sample as described above: Always interconnect those star systems, always create direct relations between them. You don't need to create decades of star systems with hundreds of worlds. Very few will be enough if they are well-established and well-interconnected.