Choreography and scripted sequences

A scripted sequence is an authored event triggered by the level: an enemy squad bursting through a door, a gunship strafing a staircase, a bridge collapsing. Choreography is Valve's word for its scripted character performances, where actors move, speak and react in the world while the player watches or plays along (Combine OverWiki: Developer commentary/Half-Life 2). Big scripted events are often called set pieces.

They are where level design, animation, audio, effects and environment art meet. The environment has to stage the event: give the player a reason to be in the right place, a clear view of it, and a space that survives the destruction.

#Directing the player's attention

Because the player controls the camera, attention is the main difficulty.

• Framing. For Half-Life 2's first Strider, Doug Wood describes "perfectly framing the Strider when it appears", which took many small tweaks (Combine OverWiki: Developer commentary/Half-Life 2). See sightlines and vistas.
• Movement draws the eye. When playtesters missed the Citadel, the team "added birds flying towards the structure" (Combine OverWiki: Developer commentary/Half-Life 2).
• Signals after the event. Some players missed that gates had opened, so the team added smoke, an alarm klaxon and a spinning light (Combine OverWiki: Developer commentary/Half-Life 2).
• Positioning the player. For Episode Two's final battle, Chris Chin's team "tried to increase the odds that the player would end up in the best possible position for the show" (Combine OverWiki: Developer commentary/Half-Life 2: Episode Two). Leslie Hall's team designed one battle's exit "purely to give the player a view from above" of a scripted event (Combine OverWiki: Developer commentary/Half-Life 2: Episode Two).

#Flexible and conditional scenes

Valve's choreography is built to adapt to the player. Bill Fletcher explains that "any part of the scene might need to lengthen, contract, or even pause" (Combine OverWiki: Developer commentary/Half-Life 2). In Eli's Lab the scene pauses if the player wanders off and resumes when they return; players "just needed enough subtle clues to know where we wanted them" (Combine OverWiki: Developer commentary/Half-Life 2). Dhabih Eng notes that "in our choreo scenes, we have the player trapped for a bit", so the team added interactive details for players who couldn't stand still (Combine OverWiki: Developer commentary/Half-Life 2).

Scripted events can also be conditional. On the bridge, Half-Life 2's gunship only crashes into the cars if the player and the gunship are in the right positions; otherwise it dies normally (Combine OverWiki: Developer commentary/Half-Life 2). On the lighthouse stairs, trigger volumes tell the gunship to pick a flight path that matches the player's height (Combine OverWiki: Developer commentary/Half-Life 2).

#Set pieces at Naughty Dog

Naughty Dog's GDC 2010 talk by Neil Druckmann and Bruce Straley describes Uncharted 2 as an attempt to create "an interactive summer blockbuster", pairing big action set pieces with grounded allies so players cared about the outcome (GDC Vault: Creating the Active Cinematic Experience of…). Co-lead designer Richard Lemarchand's postmortem the same year called the set pieces "extravagant" and predicted to be "enormously time-consuming"; the train level was "an evil monster of a level" (Engadget: GDC: 'Among Friends: An Uncharted 2…). Its problems forced fixes that helped the whole game: "If it works in train, it must work everywhere" (Engadget: GDC: 'Among Friends: An Uncharted 2…).

Levels began as basic geometry playtested by "anyone that came within arm's reach", and artists filled in detail afterwards (Engadget: GDC: 'Among Friends: An Uncharted 2…). See blockout.

#Related terms

environmental storytelling, sightlines and vistas, critical path, ludonarrative dissonance, playtesting spaces.

#Further reading and watching