GrimCo
Hero
Most of my nWoD/CoD games were essentially sandboxes. They were very minimal prep, usually few short bulletpoints, but heavy on improv. One thing that made it easy to do is setting. I used real world in real time (so if first session was on 2.9.2012, in game it's also 2.9.2012). So, whatever happens in the world, it happens in game. Also, games always started in our home town and all characters needed to be local and know each other. With that in place, it's very easy to improv because everything is very familiar, i just did few supernatural spins on some stuff. Before starting game, everyone would told me how they came to know supernatural things are real ( be it they witnessed something, or their characters became something). Once game starts, it's all on players. What they want to do, how they wanna do it, where they wanna go etc. I'm just there to run the world.
In D&d, my most recent sandbox game has 5 shortish bullet points of campaign notes and half of them are names of monsters i wanted to try, name of the city they are in, main factions and who is at war with who. That's it. They got description of setting, city they are starting in, what's happening in city and immediate surrounding and that's pretty much it. Everything else is blank canvas. Players, trough their actions and interests are ones that give prompts. If they want explore ruins of ancient civilization, i make ruins. If they wanna start smuggling operation, i'll make something that's profitable so they can smuggle it (along with competition and authorities that wanna stop them). If they wanna do slice of life and just go around town, talk to people, do mundane stuff, we can do that to. This kind of play requires very engaged players who are both proactive and have developed both their characters and party motives and goals, along with plans of how to achieve them. Even then, people have sessions where they aren't at their A game. Then i throw some hooks or make them part of someone else's problem (wrong place, wrong time kind of stuff).
In D&d, my most recent sandbox game has 5 shortish bullet points of campaign notes and half of them are names of monsters i wanted to try, name of the city they are in, main factions and who is at war with who. That's it. They got description of setting, city they are starting in, what's happening in city and immediate surrounding and that's pretty much it. Everything else is blank canvas. Players, trough their actions and interests are ones that give prompts. If they want explore ruins of ancient civilization, i make ruins. If they wanna start smuggling operation, i'll make something that's profitable so they can smuggle it (along with competition and authorities that wanna stop them). If they wanna do slice of life and just go around town, talk to people, do mundane stuff, we can do that to. This kind of play requires very engaged players who are both proactive and have developed both their characters and party motives and goals, along with plans of how to achieve them. Even then, people have sessions where they aren't at their A game. Then i throw some hooks or make them part of someone else's problem (wrong place, wrong time kind of stuff).