Just about no matter what a GM does, there's a chance that the players can go entirely off-script in an adventure and just head out to do their own thing. That can be frustrating for a GM who's trying to get them to do an adventure, but isn't that what RPGs are all about? It's with that in mind that Paizo has created their Starfinder Galaxy Exploration Manual in more a "sandbox" style.
From the post:
Paizo has a long history of supporting our games with robust adventure content: Adventure Paths, Organized Play scenarios, single volume modules, and more. All of these adventures have one thing in common: they have a clear story, and while every GM changes an adventure to suit their table, my role as a developer has been to give both GM and players a complete story with a beginning, middle, and end that rises to a satisfying finale. But what if that’s not the kind of adventure you like to run or play in? What if you want something more open… where the players can go where they want, making the story up themselves as they explore and interact with newly-discovered NPCs and mysterious creatures? What if you want to leave the “theme park” style adventure for something more like a “sandbox”?
I’m very happy to say: the Starfinder Galaxy Exploration Manual is the book you’ve been waiting for.
When Joe Pasini, lead developer of the Galaxy Exploration Manual, asked me to write the Sandbox Adventures chapter for this book, I was both excited and intimidated. Making a sandbox campaign is a tremendous logistical challenge, but it’s also highly rewarding—as any of you who have played in sandbox games can attest. And because sandbox-style games have a long history in our hobby, there’s a lot of advice on this topic out there already, much of it written by simply brilliant creators. My job was clear: to take the best of that advice and then fine-tune it to the unique qualities and attributes of the Starfinder RPG.