In my world, I build sandboxes for ranges of levels. So start out we have some sort of base, and then there are tons of adventure locations all around that base. Players explore and discover what they want. There are NPCs (Good, Evil, and everything in between) who have agendas for the area so the PCs may run afoul of those agendas. The world is a living breathing place. I have stuff happening all the time unrelated to what the group is doing. As a group gains levels, that sandbox might grow into a region or nation depending on the size. Maybe a city or large town comes into the picture.Without, uh.. de-railing this too much further, "sandbox" could be an offensive and derogatory term too, in that it is also broadly metaphorical and reliant on the contextual language surrounding it for definition. Maybe it would be less derogatory and offensive if we just didn't use any words or discuss anything at all..? The early portion of this thread was wild to read.
I like the Lego idea to discuss the amount of content and connections, but I wonder if the difference you are making here is more about the connections? I.e. a more pre-connected sandbox where there's a sprawling potential narrative frame below the spatial map, directing players through the world on suggested paths vs. one where there are less or no pre-defined narrative connections? So town A either has a bar and a castle, near town B and a dungeon A, all viable locations for adventure or town A has a bar under attack by a faction from town B, a castle with a princess who needs their sword retrieved from dungeon A and so on. So is the sandbox inherently joined up in a way which doesn't require the spatial element or are those elements the only or primary connections?
Smart! I like to think the sort of concentric waves of levelled content approach is a different kind of abstraction which guides play, in the same vein as my suggestion. The map itself is obviously one where the players might make gameplay decisions, but the contours of that map can be guided by several factors such as narrative connections, level bands, other things which impress upon the spatial layer (incentivising or disincentivizing choices) where the players get their information.In my world, I build sandboxes for ranges of levels. So start out we have some sort of base, and then there are tons of adventure locations all around that base. Players explore and discover what they want. There are NPCs (Good, Evil, and everything in between) who have agendas for the area so the PCs may run afoul of those agendas. The world is a living breathing place. I have stuff happening all the time unrelated to what the group is doing. As a group gains levels, that sandbox might grow into a region or nation depending on the size. Maybe a city or large town comes into the picture.
A second option is to just start in a major city like Ptolus and spend their entire careers adventuring there. The city is the sandbox and when they leave it they are higher level. The key is to keep having your NPCs advancing their agendas at the same time as the PCs. That way the world seems alive.