The Sierra Creative Interpreter (SCI) was a game engine developed by 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 in 1988 and powered many of Sierra’s adventure games through the 1990s. It introduced higher-resolution graphics, a point-and-click interface, a more sophisticated scripting language, and support for richer audio and animation.

Development

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.

To meet this challenge, Sierra engineer Jeff Stephenson proposed a completely new, object-oriented interpreter. 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.”

The result was SCI (initially called LSCI for Large-model Script Code Interpreter), a virtual “bytecode” engine that could be compiled for any platform.

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 issue. In practical terms, SCI scripts could define classes for rooms, actors, puzzles, etc., making the engine more flexible.

King’s Quest IV (1988) was the first title to employ Sierra’s Creative Interpreter engine, demonstrating the engine’s expanded multimedia support. 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. The Colonel's Bequest

|-

| SCI1

|-

| SCI1.1 Quest for Glory IV

Notable games

  • 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 I-II
  • Freddy Pharkas: Frontier Pharmacist
  • EcoQuest I-II
  • The Laura Bow Mysteries (The Colonel's Bequest; The Dagger of Amon Ra)
  • The Sierra Network (Later renamed to the ImagiNation Network)
  • The Realm Online

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.

References

  • List of SCI developed games on MobyGames