Editing Sierra Creative Interpreter

{{Short description|Game engine developed by Sierra On-Line}}
{{notability|date=May 2025}}
{{Infobox software
| title                  = Sierra Creative Interpreter
| name                   = Sierra Creative Interpreter
| logo                   = <!-- [[File: ]] -->
| screenshot             =
| caption                = Screenshot from King’s Quest V (1990), showcasing its VGA graphics and point-and-click interface powered by Sierra’s Creative Interpreter (SCI).
| author                 = Jeff Stephenson
| developer              = [[Sierra Entertainment|Sierra On-Line]]
| released               = {{start date and age|1988|09|p=y}}
| discontinued           = 1996
| latest release version = 
| latest release date    = {{start date and age|1996|09|23|p=y}}
| programming language   = 
| operating system       = [[MS-DOS]], [[Microsoft Windows|Windows]], [[Classic Mac OS]], [[AmigaOS]]
| platform               = [[x86]] 
| size                   = 
| language               = [[English language|English]]
| genre                  = [[Game engine]]
| license                = [[Proprietary software]]
}}

The '''Sierra Creative Interpreter (SCI)''' was a game engine developed by [[Sierra Entertainment|Sierra On-Line]] in the late 1980s as a successor to the earlier AGI ([[Adventure Game Interpreter]]) engine. SCI first appeared with ''[[King's Quest IV|King’s Quest IV]]'' in 1988 and powered many of Sierra’s adventure games through the 1990s. It introduced higher-resolution graphics, a [[Point and click|point-and-click]] interface, a more sophisticated scripting language, and support for richer audio and animation.<ref name="SCIWiki">{{cite web |title=Sierra Creative Interpreter |work=SCI Wiki – Sierra Help Pages |url=http://sciwiki.sierrahelp.com/index.php?title=Sierra_Creative_Interpreter |access-date=3 May 2025 |url-status=live}}</ref><ref>{{cite book | last=Fernández-Vara | first=Clara | chapter=Shaping Player Experience in Adventure Games: History of the Adventure Game Interface | editor-first=Olli | editor-last=Leino | editor-first2=Hanna | editor-last2=Wirman | editor-first3=Amyris | editor-last3=Fernandez | title=Extending Experiences: Structure, Analysis and Design of Computer Game Player Experience | publisher=Lapland University Press | location=Rovaniemi | year=2008 | pages=210–227 | isbn=978-952-484-197-9 | url=https://www.academia.edu/39681183/Extending_Experiences | access-date=3 May 2025 }}</ref>

== 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" />

== History ==
SCI was developed in successive versions, each offering technical advancements:

{| class="wikitable sortable"
! Version !! Year !! Graphics / Resolution !! Interface & Engine Advances !! Representative titles
|-
| '''SCI0'''<ref name="SCIWiki" /> || 1988 || 320 × 200, 16-color [[Enhanced Graphics Adapter|EGA]] || Text-parser interface; engine debut || ''[[King's Quest IV|King’s Quest IV]]''<ref>{{cite web |title=King's Quest IV Manual |url=https://www.abandonwaredos.com/docs.php?sf=king_s_quest_iv_manual.txt&st=manual&sg=King%27s+Quest+IV%3A+The+Perils+of+Rosella&idg=469 |website=Abandonware DOS}}</ref>
|-
| '''SCI1'''<ref name="SCIWiki" /> || 1990 || 256-color [[Video Graphics Array|VGA]] || Icon-based point-and-click [[Graphical user interface|GUI]] || ''[[King's Quest V|King’s Quest V]]''; ''[[Space Quest IV]]''; ''[[Leisure Suit Larry in the Land of the Lounge Lizards|Leisure Suit Larry I]]'' (VGA remake)<ref name="Sierra Game Versions">{{cite web |title=Sierra Game Versions |url=https://wiki.scummvm.org/index.php/Sierra_Game_Versions |website=ScummVM Wiki}}</ref>
|-
| '''SCI1.1'''<ref name="SCIWiki" /> || 1992 || 256-color VGA (enhanced) || Added enhanced animation and sprite scaling || ''[[King's Quest VI|King’s Quest VI]]''; ''[[The Dagger of Amon Ra|Laura Bow: The Dagger of Amon Ra]]''<ref>{{cite web |title=Sierra Creative Interpreter |url=https://spacequest.fandom.com/wiki/Sierra_Creative_Interpreter |website=Space Quest Omnipedia}}</ref>
|-
| '''SCI2'''<ref name="SCIWiki" /> || 1993 || 640 × 480 [[Super VGA|SVGA]], 256 colors || 32-bit protected mode; further engine refinements || ''[[Gabriel Knight: Sins of the Fathers]]'';<ref>{{cite journal | last=Veugen | first=J. I. L. | year=2008 | title=Thinking out of the box (and back in the plane): Concepts of space and spatial representation in two classic adventure games | journal=Eludamos: Journal for Computer Game Culture | volume=2 | issue=2 | pages=215–239 | url=https://research.vu.nl/ws/files/2345227/210994.pdf | access-date=3 May 2025}}</ref> ''[[Quest for Glory: Shadows of Darkness|Quest for Glory IV]]''<ref name="Sierra Game Versions"/>
|-
| '''SCI3'''<ref name="SCIWiki" /> || 1996 || Native Windows 95 rendering || Final iteration; native Windows 95 support || ''[[Leisure Suit Larry: Love for Sail!|Leisure Suit Larry 7]]''; ''[[Phantasmagoria: A Puzzle of Flesh|Phantasmagoria II]]''<ref name="Sierra Game Versions"/>
|}

== Technical specifications ==
SCI was an interpreted engine using a proprietary scripting language with object-oriented features. It supported platforms including [[MS-DOS]], [[Microsoft Windows|Windows]], Macintosh, [[Amiga]], and [[FM Towns]].
Graphics support ranged from 16-color EGA in SCI0 to 256-color SVGA in SCI2/SCI3. SCI also supported a variety of sound hardware, including [[Ad Lib, Inc.|AdLib]], [[Sound Blaster]], and [[Roland MT-32]].<ref>{{cite web |title=King's Quest V Manual |url=https://www.abandonwaredos.com/docs.php?sf=king_s_quest_v_manual.txt&st=manual&sg=King%27s+Quest+V%3A+Absence+Makes+the+Heart+Go+Yonder%21&idg=481 |website=Abandonware DOS}}</ref>

== Notable games ==
* ''[[King's Quest|King’s Quest]] IV-VII''
* ''[[Space Quest]] III-VI''
* ''[[Leisure Suit Larry]] II-VII''
* ''[[Police Quest]] II-IV''
* ''[[Quest for Glory]] I-IV''
* ''[[Gabriel Knight]] I-II''
* ''[[Phantasmagoria (video game)|Phantasmagoria]] I-II''
* ''[[Freddy Pharkas: Frontier Pharmacist]]''
* ''[[EcoQuest: The Search for Cetus|EcoQuest]] I-II''

== Legacy and influence ==
SCI was one of the leading adventure game engines of its time, alongside LucasArts' [[SCUMM]]. It influenced modern engines like [[Adventure Game Studio]]. Preservation efforts include support for SCI games in [[ScummVM]], which merged with the FreeSCI project in 2009.<ref>{{cite web |title=ScummVM Adds Support for Sierra Classics |url=https://www.linux.com/news/scummvm-adds-support-sierra-classics/ |website=Linux.com}}</ref>

== References ==
{{Reflist}}

== External links ==
* {{YouTube|id=K3s0nW1FBN8|title=Interview with SCI engineer Jeff Stephenson}}
* [https://www.mobygames.com/group/6528/game-engine-sierras-creative-interpreter-sci/ List of SCI developed games on MobyGames]

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