Diamond (branch and merge) stories

Another way to limit the exponential growth of a branching is to create pinch points where the various branches converge, before diverging again. The pinch points may correspond to the narrative points of a traditional linear story. There may be some bad ends along the way, similar to a gauntlet structure, but these tend to be far fewer, and more obvious to the player. A number of endings are typically included, reflecting the impact of choices made along the way.

In order for the events before one of the pinch points to affect the options or outcome of the next section (for the events of Act 1 to influence Act 2) the game now has to track significant choices in variables rather than just rely on where the player is in the story. This is a significant departure from the structures presented so far as the game's state is a combination of these variables and where in the story the player is.

In table top role-playing games (TTRPGs) this additional state is often recorded on a character sheet and includes how good the PC is at different kinds of task, the damage they've taken, and their collection of items acquired along their journey (their inventory).