While the structure of an experience can be considered by looking at its micro composition and macro composition, these scales must be tied together in a way that makes the entire experience cohesive for the audience. This is done by creating arcs within the experience that span the micro, macro, and meta scales. These arcs can be dramatic arcs (for narrative experiences), musical arcs (for audio experiences), emotional arcs (for certain types of visual experiences), etc. In the case of interactive experiences (in particular games), these arcs are actually the goals of the player.
Arcs have durations. They begin, for example, when a conflict starts or a goal is acquired, then end when the conflict is resolved or the goal is obtained. It is critical to understand how to interleave arcs of different durations to create a psychological force that "pulls" the audience through the experience.
- Micro Arcs: these are generated and resolved constantly, being very specific, tactical, or transitory in nature, such as a conversation between two characters, killing a particular enemy, avoiding an incoming grenade, etc. Micro goals occur within individual segments of the experience.
- Macro Arcs: these are generated and resolved during the experience at fairly regular intervals and direct the audience through the experience, such as two characters falling in love, reaching a new level, saving a kidnapped ally, etc. They also include arcs that are only resolved at the end of the experience, such as a character resolving his childhood conflict with his father, rescuing the prince, killing the evil lord, etc.
- Meta Arcs: these are generated and resolved outside the actual experience itself, such as your new perception of a character as an adult that is different from when you were a child, making a fan edit of a movie, becoming a professional player of a game, completing all titles in a series, etc.
Arcs need to be constructed so that new ones are generated as old ones are resolved in order to keep the audience immersed. There should be at least a segment arc, an episode arc, and a title arc at any one time. To really heighten this effect, you need to make the arcs interlocking (as shown on the chart to the right) so that when one arc expires, one or more other arcs are already partially completed. The psychological need to see partially-finished arcs to completion is very strong, so most people will feel compelled to finish the next arc (by which time they will have another partially completed arc, of course). Note that there can be arcs that start in the middle of one episode and end in the middle of a different one; arcs do not have to be aligned with segment or episode boundaries (although many often are). The chart shows an example of how macro arcs might interlock, but micro arcs and meta arcs can be interlocked in a similar manner.
Long arcs can't just have a beginning and an end. They must be intermittently maintained or advanced so that their resolution doesn't come as a complete surprise (i.e., anticipation must be maintained). This can be done very directly and explicitly (a recurring enemy that is in every episode), or it can be done subtly (as in a good murder mystery). Even just a bit of dialog or a quick reaction shot can be enough to keep an arc going. Just make sure the audience is not confused or uninterested when the arc is resolved.
Goals in Interactive Experiences
In an interactive experience, such as a game, the affordances created by the elements of the experience will generate possible goals for the player (and the actions that lead to those goals). Goals are the primary way to explore an interactive possibility space as they are chosen to be pursued by the player. Goals are generally what the player perceives the game to be "about" (while the designers of the game generally think the game is "about" the type of engagement it delivers). A first-person shooter might be "about" defeating enemies and getting better weapons to the player (which are their goals), while a designer would talk about challenge and accomplishment being the types of engagement the game is "about". However, designers must think in terms of the player's goals when actually building the game. The type of engagement delivered is an outcome, the player's goals are how you deliver that outcome.
An interactive arc begins when a goal is acquired and ends when that goal is obtained (or when it is abandoned in some cases). The goals in an interactive experience should generally be synchronized with the non-interactive arcs that might be part of the experience as well. By making the goals of the player align with the dramatic or emotional arcs of the experience, it will be easier to create resonance between different engagement types, which can greatly increase how engaging the experience is. Maintaining interactive arcs is often done through showing progress towards the goal (experience gained, currency gained, quest progress, etc.). When traversing an interactive arc, there is also the potential to be set back (even to the beginning of the arc), if progress towards a the goal in question can be lost. This is not automatically a bad thing, as it can create an interesting loop of actions as the goal is continually pursued.
In games, arcs can often come from elements that wouldn't normally be thought of. For example, particular weapons or abilities might have their own arcs. These arcs would begin when the weapon or ability was acquired, be maintained when the weapon or ability was used, and end when the weapon or ability was superseded or was otherwise no longer needed (i.e., there are no interesting possibilities remaining that involve that weapon or ability). It can be very useful to think about items and abilities in this manner, so that it is clear where they are needed and so that different items and abilities will have interlocking arcs.
Explicit, Implicit, and Emergent Goals
Goals can be either explicit, implicit, or emergent. Explicit goals are given to the player directly by the rules of the game ("score 100 points to win"). Implicit goals are not explicitly stated, but are definitely part of the design of the game ("I can see a tower in the distance, so I guess I should go there"). Emergent goals are completely player-generated ("I wonder if I can write my name with bullets on this wall?"). Goals usually don't fall cleanly into one of these buckets; there is a continuum from completely explicit (something directly stated and required in order to advance in the game at all) to completely emergent (something completely novel that has nothing to do with the normal play of the game). A highly directed experience is one driven primarily (or exclusively) by explicit goals, while a undirected experience is one that uses emergent goals to drive most of its engagement.
In order to be effective, goals must be driven by the five fundamental human motivations (autonomy, mastery, connection, novelty, and safety). Goals that satisfy these motivations can create the tension that drives engagement.
A player can only have a goal if the elements of the game have an affordance for that goal (and the actions that lead to that goal). The goal cannot just be a possibility, it must be a perceived possibility. While properly designed goals are critical to making an engaging experience, a goal that is not accessible to a player due to poor signifiers might as well not exist. A goal could also be inaccessible due to a lack of knowledge or skill, which is why the learning curve of the audience as it goes through an experience must be considered.