Editing Sierra Creative Interpreter (section)

== Development ==
[[File:Sierra-Interaction-Magazine---Ad---KingsQuest5.jpg|thumb|Magazine advertisement for ''[[King's Quest V]]'', highlighting the advanced technical capabilities enabled by Sierra's SCI engine.]]Sierra realized AGI (originally developed for the IBM PCjr) was “under-equipped” for the new multimedia era.<ref name="MobySCI">{{cite web |url=https://www.mobygames.com/group/6528/game-engine-sierras-creative-interpreter-sci/ |title=Game Engine: Sierra's Creative Interpreter (SCI) |website=MobyGames |access-date=3 May 2025 |url-status=live}}</ref>

To meet this challenge, Sierra engineer Jeff Stephenson proposed a completely new, object-oriented interpreter.<ref name="Retro365KQ">{{cite web |last=Krogtoft |first=Ernst |title=King's Quest – IBM, Tandy, and Beyond |url=https://retro365.blog/2024/04/05/kings-quest-ibm-tandy-and-beyond/ |website=Retro365 |date=5 April 2024 |access-date=3 May 2025}}</ref> As he recalls, “AGI was written in such a way that it was going to take a major rework of the entire game engine…and so that’s when I pitched Ken on SCI…let’s go with a whole new language, we’re going to have to rewrite this thing anyway, let’s make things better.”<ref name="BenshoofSCI">{{cite web |url=https://www.benshoof.org/blog/sci-scripts |title=Sierra Creative Interpreter—Scripts |work=Benshoof.org |date=2023-07-04 |access-date=2025-05-03 |url-status=live}}</ref>

The result was SCI (initially called LSCI for Large-model Script Code Interpreter), a virtual “bytecode” engine that could be compiled for any platform.<ref name="MobySCI" /> As [[Roberta Williams]] explained, SCI was designed as “a virtual machine language which means that it will work on any machine…Each machine format has its own version of SCI. Our games are never IBM conversions.”<ref name="RobertasBequest">{{cite web |last=Byron |first=Tom |title=Roberta's Bequest: An Interview with Sierra On‑Line's Roberta Williams |website=START Magazine – Classic Computer Magazine Archive |url=https://www.atarimagazines.com/startv4n8/robertas_bequest.php |date=March 1990 |access-date=3 May 2025 |url-status=live}}</ref>

SCI’s design drew on then-modern programming ideas. Stephenson was influenced by Object-Oriented languages like Smalltalk, which he discovered in a 1981 [[Byte (magazine)|BYTE]] issue.<ref name="BenshoofSCI" /> He rewrote Sierra’s scripting language into a more structured, object-oriented form. As one retrospective notes, “Stephenson completely rewrote the language…going from a simplistically cryptic scripting language to a full-fledged modern programming language reminiscent of C++, incorporating all the latest thinking about object-oriented coding.”<ref name="MaherSierraCreative">{{cite web |last=Maher |first=Jimmy |title=Sierra Gets Creative |url=https://www.filfre.net/2016/08/sierra-gets-creative/ |website=The Digital Antiquarian |date=5 August 2016 |access-date=3 May 2025}}</ref> In practical terms, SCI scripts could define classes for rooms, actors, puzzles, etc., making the engine more flexible.

''[[King's Quest IV|King’s Quest IV]]'' (1988) was the first title to employ Sierra’s Creative Interpreter engine, demonstrating the engine’s expanded multimedia support.<ref>{{cite journal|last=Greenberg|first=Raz|title=The Animation of Gamers and the Gamers as Animators in Sierra On-Line's Adventure Games|journal=Animation|publisher=SAGE Publications|volume=16|issue=1-2|pages=83–95|year=2021|doi=10.1177/17468477211025665|url=https://www.researchgate.net/publication/353266870_The_Animation_of_Gamers_and_the_Gamers_as_Animators_in_Sierra-On-Line%27s_Adventure_Games|access-date=3 May 2025|doi-access=free}}</ref> It featured a full orchestral score by [[William Goldstein]], one of the earliest uses of a Hollywood-style soundtrack in a computer game. These audio enhancements illustrated SCI’s ability to handle more complex musical arrangements and contributed to a more cinematic adventure experience.<ref name="MaherSierraCreative" />