So, here's the twist: Even though I am going to great lengths to shape the world, and the environment... the species & language terminology, and so forth (I have a lot that I created before, so it's mostly modification and paring down, in that regard), I do want a sandbox environment.
Sandbox is totally unrelated to what the setting is. I can use the Dragonlance saga to run a sandbox, and the campaign that usually goes with it is known as one of the strictest railroads ever.
Do you want to run that sandbox yourself? Just use the setting and run it. Sandbox set-up works with freeform and system games, with pre-defined events and without them, whether said events can be thwarted or not, with a narrative approach or a sim one... If I know a set-up that's close to universal, it's the sandbox one. Oh yes, in case it's not obvious: It's also my preferred approach to games
It's also an approach you can't impose on others, if you want to define the setting for use from other GMs as well. So just write info that would be useful to sandbox GMs and they'll be more likely to gravitate towards using it-given time.
It's also the approach that needs the most contribution from players. So you need a pool of players that a) love the setting, b) are ready to read a lot of setting info, and c) are ready to have their characters acting proactively, which is the number one requirement to sandbox games IME
It's not impossible, but you need to pimp your game
. First, write your opening post as described in Moraline's advice. Include a clear warning that it's going to assume some reading.
Then it's time you do some hard work. Distill the setting info down to what a non-educated member of a non-travelling caste would know. Put it in quote in the starting post, titled EVERYTHING YOU *NEED* TO KNOW (assuming it's a system game, the basic info on system goes there, too.
Then add an "you might want to know this, too, but it's not necessary" spoilerblock with links to the setting wiki (or whatever format you've chosen).
Sure, you can dump the setting and just write about it. This just lessens the entry barrier, doesn't eliminate it-and ultimately, you need people that aren't scared of doing some reading.
But, most importantly, when doing your opening post, tell me about your setting! Why would I want to devote time and energy to your world and not to Generic Fantasy Game #1234567890? Don't make me read your setting to find out, that's a common mistake (hint: I won't read it, there are enough other settings I can read sitting on my drive, and I doubt I'm the only one).
You obviouisly love the setting. Tell me why.
You want me to feel the same way. Tell me what it gives me and how and improves the game.
Make me want to play in it. Share the love !
I'll send you by PM a couple links explaining how to run a sandbox game with a plot and with a minimum of effort, just in case you need them (mostly, because these are links to forum discussions where people more experienced than me explain how they run sandbox games).
Now, running a sandbox is anything but hard. The tricks are in minimising the amount of work you need to do!
Sandbox RPs are probably the hardest to set up, easiest to start, and hardest to keep going... In my opinion!
It's easiest, easiest, easiest in my opinion. Guess we can agree to disagree
Setting up the world needs planning and careful structuring, it also requires rules for world-building by players - a discussion earlier in this thread talked about how some GMs are okay with players defining the smaller aspects of the world such as whether there is a fire extinguisher in the room, but prefer to define the larger aspects themselves - how many rooms there are, for example. Other GMs want to define every little detail and others are okay to let players define even major aspects of the world.
Yes, although I wouldn't call that "rules". I'd say that you just need to let the players know how much you're fine with them defining.
I personally think that if one is creating a sandbox game, then one needs to define the world andlay down these principals at the start. A story based game, by contrast, can have the world unfolding as it is explored...
Actually, the "original" (read: the first definition I'm aware of) definition of sandbox includes the world unfolding as it is explored. In it, you start at X and know enough to get by. What else is beyond the hills, other than what you've heard about (and 90% of it is wrong anyway)? Go and see for yourself!
You can have the world laid out, sure. It's just not the only, or dare I say, even the expected mode of playing.