I don’t run prewritten adventures too often. This is because the greatest kicks I get from playing the GM role in an RPG come from being surprised by and discovering the world with my players. My campaigns tend to be very sandboxy, starting with a sketch of the world that is fleshed out as we play. Plots emerge by themselves by having the world react to players’ actions. I’ve often had conversations with other GMs that think this may be a lot of work, or overwhelming, but I honestly find it the most natural, low-effort, and rewarding way of playing the game.
This may not be true for others. I’ve played with great game masters that feel like they need to know where everything is and have a certain degree of control on what is going to happen next. I’ve put together a rough procedure of how I go about from basic worldbuilding to running a campaign where players decide what to explore next, and how the setting becomes more solid as we discover it together.
Creating a rough sketch with strong vibes goes a long way, and allows me and my players to have a common ground from where we can start exploring. I tend to follow the first three or four steps of Ray Otus’ excellent Gygax75 challenge, which helps create a strong concept, a small region to roam around, a large adventure location, and a starting town. Step 5, where the larger world is fleshed out, I leave out so I can discover it with my players.
The work above usually takes me about a week to complete. After I come out of it, I know enough about what’s cool in that new world that I can envision some troubles my players can interact with. I set off to create some situations that are happening and that players could be interested in engaging with. These can include things like bandits going around, a missing macguffin from the local temple, two mining companies racing to gather a new resource… You know the drill.
After there are a few things in motion around the adventuring area, I create a hook for each of them. Just rumours or other ways players could learn about these things and decide whether to engage with them.
I like open tables because they allow a more flexible schedule, but they also need to be handled a bit differently. The pool of players needs to be larger, about six to ten works well for me. Every session should be as self contained as possible, because players will drop in and out. This is great, because it allows players with more limited availability to play, but it requires that sessions are a bit of a one-shot. I have managed this constraint differently in different campaigns, but it’s never been a problem as long as it’s well communicated ahead of time.
On one campaign, the base was a settlement at the border of civilisation (if it ain’t broke…), and the deal was that each session would be an expedition, and that by the end of the session characters would have to be back to the base (supplies run out, for example), whether they achieved their goal or not. Running a relatively lethal game helps with this, as players will often reevaluate how far they feel like pushing their luck. Another staple was that healing was slow, so they needed to go back to the base town to heal.
In another campaign, a magical fog surrounded the world outside main cities, bringing monsters and sickness with it. The limitation was more diegetic, as characters could not spend more than a few days out of town without suffering mutations, which the inquisitors did not like very much.
Another example was a megadungeon delve (yes, dungeons are excellent sandboxes), where each delve was a session, and we had a timer set off when there was an hour or so of game left so that they started their way back. You could easily set a verosimile reason for this, like that the dungeon sinks into the sea every morning and can only be entered during night.
The session-to-session prep is pretty light for me. I just gather notes for NPC names (and maybe a rough concept), rumours, encounters, and cool treasure. Usually 6 of each, so I can use them as a sort of tailored random table.
After the first session, I also keep a few notes on what happened, and update the world accordingly. This can be things like “the party pissed off the guild of merchants”, “the temple blew up” or “the governor of the county is Lord Tlanox, a scrawny and evil man”. I pay attention to what the players engage with, and develop some more troubles and locations in that general direction.
One aspect that is very important to me is factions. They start as a loosely defined concept, but as players interact with NPCs associated to them, accept missions from them, or just piss them off, they become more important in driving future events. For this, I use mind maps similar to the ones used in Whitehack to better understand the status quo that came from play.
The rough world sketch starts play, and I use random tables and player input to flesh out things as we go. I love asking loaded questions like “the hunter says something that reminds you of someone from your past, what is it, and who that person was?” and that way we get to build the world and the backstory of the characters (I ask players not to write 8 pages of fanfiction before play, we also discover who their characters are as we go).
This way, the world is created collaboratively. It also helps offload a lot of the cognitive weight of running games without killing me with prep. I let players decide which gods they follow, where they come from and what’s different about that place, set up local NPCs they have some rapport with, etc. I simply take note of things that may be relevant later. If I miss something, it’s usually fine. The player that came up with the snow nation of Apnir will definitely remind you whenever it becomes relevant in the game.
Consequences, consequences, consequences. Players will be engaged by seeing how their actions – and inactions – make an impact in the world around them. Completing missions will have an impact in the setting, but also not engaging with other hooks. The feeling of “the world moves on and doesn’t care about you” can be very immersive. Let your rumours age. If the players don't engage with the bandits in the north, maybe a month from now they start attacking the villages nearby, and two weeks later they're at the doors of their base city! You never have to throw away the hooks you worked on, it reduces prep while making it more interesting, and it will make the world seem alive and not spinning around them. I just roll some dice (high: good, low: bad) between sessions to see how a situation they left unattended has evolved, and they may hear more news about it in the next session.
It’s entirely possible to run a sandbox campaign with relatively low preparation and upkeep. I have experienced that it’s easier – and more fun – for me to plunge into the deep end and trust my players to sort out the details. Players will be engaged by seeing how the world reacts to their actions, and will remember the setting because they took part in building it. It may not be for everyone, but I would encourage more people to try it, as it can be really rewarding. Allow yourself to be surprised!