9 | *If they asked me, I could write a book;*
10 | *About the way you TALK, and LISTEN; And LOOK.*
12 -- with apologies to Richard Rodgers and Lorenz Hart.
16 .. image:: /images/picT.png
23 ext adventures, otherwise known collectively as interactive fiction (IF),
24 were highly popular computer games during the 1980s. As technology evolved
25 they faded from the market, unable to compete with increasingly
26 sophisticated graphical games; however, IF was far from dead. The Internet
27 grew, and Usenet discussion forums offered a focal point for fans of the
28 genre. By developing IF programming tools and systems, organising contests
29 and writing tutorials and reviews, these enthusiasts have led a revival
30 responsible for many notable works, including some whose quality arguably
31 surpasses that of the best commercial titles of the 1980s.
33 Nowadays, IF is a hobby; almost everything that you need to begin writing
34 your own text adventures is available, for free, on the Internet. While
35 expert programmers may relish the considerable challenge of creating
36 interactive fiction using a generalised language such as BASIC or C,
37 specialist IF tools have largely solved the fundamental world-building
38 issues. The most common systems are Graham Nelson's Inform -- our subject
39 matter -- and Mike Roberts' TADS (Text Adventure Development System). New
40 hopefuls arrive each year, but few achieve widespread acceptance; the
41 majority of today's IF (and virtually all the works generally regarded as
42 interesting, innovative, sophisticated, etc.) have been created with
43 either one or the other. In our view, only TADS bears comparison with
44 Inform in popularity, in being able to handle simple and complex stories,
45 and in availability on PCs, Macs, hand-held devices and a wide variety of
46 other computers. But, since you're reading our guide, we'll assume that
47 you've already made a choice, and decided to give Inform a try.
49 We aim to provide a grounding in Inform basics. When you have learnt a
50 little about it, you'll be able to design simple games for your friends to
51 play and, as you become more accomplished, which you can share via the
52 Internet with enthusiasts worldwide. However, if you simply want to play
53 [#play]_ games written by others -- rather than write them yourself -- then
54 you don't need to learn Inform, and this guide isn't for you.
59 Because this is only an introduction to Inform, many features are treated
60 rather superficially, or ignored altogether. The definitive text is Graham
61 Nelson's Inform *Designer's Manual* (Fourth Edition, July 2001), commonly
62 known as the DM4; you cannot hope to use Inform successfully without having
63 this splendid book by your side. Our guide should be seen merely as a
64 supplement to the DM4, offering step-by-step descriptions of those aspects
65 of Inform which are most important on first acquaintance. In any matter
66 where we seem at odds with what Graham has written, you should assume that
67 he is right and that we are, well, confused.
69 As a tutorial, this guide is intended to be printed out and then read
70 sequentially; it isn't meant for online usage or designed as a reference
71 manual, though it does provide brief summaries of Inform's language and
72 library. Our approach is to teach you about Inform through the creation of
73 three games: all short, all playable to completion. "Heidi" is just about
74 as simple as an IF game can be, but still manages to introduce a range of
75 important concepts. "William Tell", a retelling of the famous folk tale,
76 is nearly as brief but roams more widely in its use of Inform's
77 capabilities. Finally "Captain Fate" presents a comic-book hero in urgent
78 need of a change. By the end of the guide, we'll have touched on less than
79 half of Inform's capabilities, but we hope we'll have mentioned most of the
80 things that matter when you're starting out to design your first Inform
83 One final point: Inform is a powerful system, often offering several
84 different ways of tackling a particular design requirement. We've tried to
85 present things as simply and consistently as possible, but you shouldn't be
86 surprised to discover other approaches, maybe shorter, maybe more
87 efficient, than those shown here.
89 Presentation and style
90 ======================
92 Most of the guide's text appears in this typeface, except where we're using
93 words which are part of the Inform system (like ``print``, ``Include``,
94 ``VerbLib``) or are extracted from one of our games (like ``bird``,
95 ``nest``, ``top_of_tree``). Terms in **bold type** are included in the
96 glossary -- Appendix G on page 273. We switch to italic type for a
97 placeholder: for example you should read the Inform statement:
99 :samp:`print "{string}";`
101 as meaning "display on the player's screen the arbitrary character or
102 characters which are represented here by the placeholder *string*".
103 Examples might include::
105 print "Hello world!";
106 print "Fourscore and seven years ago our fathers brought forth on
107 this continent a new nation, [...] and that government of
108 the people, by the people, for the people shall not perish
111 We place the "TYPE" symbol alongside game fragments which you can type in
112 as a part of our working examples. This differentiates them from other
113 code snippets whose only purpose is to illustrate some particular feature.
117 The "TYPE" symbol doesn't really work here. Think of a better way to
118 indicate typed-in fragments.
120 Useful Internet resources
121 =========================
123 One of our basic assumptions -- along with your burning desire to learn
124 Inform and your ability to work comfortably with the files and folders on
125 your computer -- is that you have access to the Internet. This is pretty
126 well essential, since almost everything you need is available only via this
127 medium. In particular, you'll find much helpful material at these
130 * http://www.inform-fiction.org/
132 The Inform home page, maintained by Graham Nelson and a small team of
133 helpers. Most important, this is where you can find the *Inform
134 Designer's Manual* in PDF format.
136 * http://mirror.ifarchive.org/
138 The IF Archive (or actually a high-speed mirror copy of it), from which
139 you can download almost anything that's free and in the public domain.
140 For a clickable map of Inform-related parts of the Archive, see
141 http://www.firthworks.com/roger/informfaq/hh.html.
145 Prior to August 2001, the IF Archive was located elsewhere, at
146 ftp://ftp.gmd.de/if-archive/, and references to that location can
147 still occasionally be found. *Do not use* the old location: any
148 information still available from there is likely to be out-of-date.
150 * http://www.firthworks.com/roger/
152 Roger Firth's Inform pages, including the Informary (what's new in
153 Inform?), and the Inform Frequently Asked Questions (FAQ) pages.
155 * http://www.plover.net/~textfire/raiffaq/
157 A more general list of FAQs about IF authorship, covering both Inform
158 and the other main systems.
160 * news:rec.arts.int-fiction
162 The Usenet newsgroup for authors of IF, commonly known by the
163 abbreviation RAIF. Here you'll find discussion on IF technology,
164 criticism and game design issues, and fast, friendly and knowledgeable
165 assistance with your own "how do I..." questions (but please, look in
168 * news:rec.games.int-fiction
170 The complementary newsgroup for IF *players*, often known as RGIF.
174 Update these links appropriately. The newsgroups in particular are
175 mostly unused these days.
180 Becoming sufficiently conversant with Inform to be able to share it with
181 others is not something done quickly or in isolation. In getting to where
182 we are today, we have been assisted at many times and in many ways by the
183 notably supportive and good-natured people, far too numerous to list by
184 name, who make ``rec.arts.int-fiction`` such an invaluable IF resource. We
185 are grateful to you all.
187 In creating this guide, we have received specific help from a number of
188 people. First and foremost we must mention Graham Nelson, who kindly wrote
189 the Foreword, and delighted us with long and detailed lists of helpful
190 comments and suggestions on two of our drafts; also Dennis G. Jerz, who
191 patiently and skilfully edited the text, making innumerable improvements to
192 our often wayward and inconsistent prose. David Cornelson supervised the
193 Second Edition's transformation into professionally printed respectability.
194 Further assistance came from Barney Firth, Christine Firth, Harry Firth,
195 Megan Firth, Jim Fisher, Rosemary Frezza, Phil Graham, Graham Holden, Paul
196 Johnson, Yoon Ha Lee, Brian Pylant, Jo Quinn, Milos Radovanovic, Muffy
197 St. Bernard, Gunther Schmidl, Emily Short, Curt Siffert, A. Sloe, Pavel
198 Soukenik, Elise Stone, Brent VanFossen and R. Cliff Young. Thank you: it
199 is impossible to overstate the value of this freely given support and
202 The drop capitals, and their associated poem, are from "A Picture
203 Alphabet", digitised from a collection of public domain woodcuts, circa
204 1834, by Steven J. Lundeen of emerald city fontwerks.
206 All credit to the generosity of http://briefcase.yahoo.com/ for making
207 international file-sharing such a breeze.
209 Finally, of course, we owe an enormous debt of gratitude to Graham Nelson
210 for devising it all, thereby giving us the opportunity -- first
211 independently and later in enjoyable collaboration -- of using, and
212 eventually of presenting, the Inform text adventure development system.
215 | *Wallingford, England*
222 .. rubric:: Footnotes
225 If you feel confused about IF in general or about this distinction
226 between writing and playing in particular, try glancing ahead at "Just
227 what is interactive fiction?" on page 13 and at "How to play an IF game"
228 on page 209; also, you may find the Ifaq at
229 http://www.plover.net/~textfire/raiffaq/ifaq/ helpful.