Sandbox Level
The idea of Sandbox Level is something I am working on to give potential players an idea of how a game might run or at the very least how a GM envisions a game might run. Anything we can do to help facilitate getting people on the same page is a good thing.
Games can certainly progress up or down the chain as appropriate.
Level 0: Scripted sequence of encounters. The players have control over the details of the action, but where it leads is rarely in doubt. Full on roller coaster (screw railroad, these games can be fun, so I declare it a roller coaster). Subplots are only appropriate within the given channels.
Level 1: Plots are presented to the players that they can interact with. They have full control within the plot elements but much of the resolution is 'discovered' by the players, rather than devised by them. Players can develop subplots as appropriate.
Level 2: Multiple plots are presented to the players and they can choose which ones to interact with and which ones to ignore. Players have the freedom to develop their own plots and gain direct influence on the game and metagame over time. GM initiated plots are still the focus of the majority of the sessions.
Level 3: Character developed plots continue from session to session while GM initiated plots are presented often, which the players are free to engage or ignore. Characters develop their own subplots and determine how they interact with the world.
Level 4: The majority of the game revolves around player decision and interaction with the world. The GM occasionally presents plot points, which the players are free to engage or ignore. The game world is strongly influenced by the actions of the players.
Level 5: The players drive all facets of plot. The GM does not develop plots or storylines, but instead develops what the players give him.