A Design System for
Interactive Fiction
 
 
Inform 7
Inform is a design system for interactive fiction, a new medium for writers which began with adventure games in the late 1970s and is now used for everything from literary narrative fiction through to plotless conceptual art, and plenty more adventure games too. Since its introduction in 1993, Inform has become a standard tool.
Three years in the making, Inform 7 is a radical reinvention of the way interactive fiction is designed, guided both by contemporary work in semantics and by the practical experience of some of the world's best-known writers of IF.
An easily learned but flexible one-window user interface makes the cycle of writing and testing rapid and painless. Inform creates, manages, edits, indexes, tests, and even helps to publish works of IF without fuss or screen clutter.
Inform itself is a free download. It produces works playable on a vast range of computers: distribute these free or for profit with no rights implications or financial obligations to the author of Inform. Convenient publishing features include help with drawing maps, producing websites, cover art, bibliographic data, walkthrough solutions and more.
 
In place of traditional computer programming, the design is built by writing natural English-language sentences:
  1. ‣Martha is a woman in the Vineyard.
  2. ‣The cask is either customs sealed, liable to tax or stolen goods.
  3. ‣The prevailing wind is a direction that varies.
  4. ‣The Old Ice House overlooks the Garden.
  5. ‣A container is bursting if the total weight of things in it is greater than its breaking strain.
Inform's power lie in its ability to describe: to lay down general rules about "closed doors", or "bursting containers", or "unmarried men liked by Martha". At its best, expressing IF in natural language results in source text which is not only quick to write, but very often works first time, and is exceptionally readable.
In the left hand panel of the window, simply type a description of the work in natural language - in English sentences, that is. Click the Go button, and Inform replies in the right hand panel: if it finds mistakes, these are thoroughly explained - for instance, with examples of correct and incorrect usage - but if all is well, the game begins playing. It can be explored just as a player of the final work would explore it.
Should you play for a while, say, getting 20 turns into the story, and then find a finicky mistake - or something that could be improved - simply amend the source text back on the left and click Replay: then watch as your steps are retraced back to where you left them, and resume.
Inform remembers not only the latest moves, but all previous plays, and builds a Skein of solutions to branching narratives: it can later test that all these alternative routes through play work as intended.