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.
14 .. image:: /images/picT.png
17 ext adventures, otherwise known collectively as interactive fiction (IF),
18 were highly popular computer games during the 1980s. As technology evolved
19 they faded from the market, unable to compete with increasingly
20 sophisticated graphical games; however, IF was far from dead. The Internet
21 grew, and Usenet discussion forums offered a focal point for fans of the
22 genre. By developing IF programming tools and systems, organising contests
23 and writing tutorials and reviews, these enthusiasts have led a revival
24 responsible for many notable works, including some whose quality arguably
25 surpasses that of the best commercial titles of the 1980s.
27 Nowadays, IF is a hobby; almost everything that you need to begin writing
28 your own text adventures is available, for free, on the Internet. While
29 expert programmers may relish the considerable challenge of creating
30 interactive fiction using a generalised language such as BASIC or C,
31 specialist IF tools have largely solved the fundamental world-building
32 issues. The most common systems are Graham Nelson's Inform -- our subject
33 matter -- and Mike Roberts' TADS (Text Adventure Development System). New
34 hopefuls arrive each year, but few achieve widespread acceptance; the
35 majority of today's IF (and virtually all the works generally regarded as
36 interesting, innovative, sophisticated, etc.) have been created with
37 either one or the other. In our view, only TADS bears comparison with
38 Inform in popularity, in being able to handle simple and complex stories,
39 and in availability on PCs, Macs, hand-held devices and a wide variety of
40 other computers. But, since you're reading our guide, we'll assume that
41 you've already made a choice, and decided to give Inform a try.
43 We aim to provide a grounding in Inform basics. When you have learnt a
44 little about it, you'll be able to design simple games for your friends to
45 play and, as you become more accomplished, which you can share via the
46 Internet with enthusiasts worldwide. However, if you simply want to play
47 [#play]_ games written by others -- rather than write them yourself -- then
48 you don't need to learn Inform, and this guide isn't for you.
53 Because this is only an introduction to Inform, many features are treated
54 rather superficially, or ignored altogether. The definitive text is Graham
55 Nelson's Inform *Designer's Manual* (Fourth Edition, July 2001), commonly
56 known as the DM4; you cannot hope to use Inform successfully without having
57 this splendid book by your side. Our guide should be seen merely as a
58 supplement to the DM4, offering step-by-step descriptions of those aspects
59 of Inform which are most important on first acquaintance. In any matter
60 where we seem at odds with what Graham has written, you should assume that
61 he is right and that we are, well, confused.
63 As a tutorial, this guide is intended to be printed out and then read
64 sequentially; it isn't meant for online usage or designed as a reference
65 manual, though it does provide brief summaries of Inform's language and
66 library. Our approach is to teach you about Inform through the creation of
67 three games: all short, all playable to completion. "Heidi" is just about
68 as simple as an IF game can be, but still manages to introduce a range of
69 important concepts. "William Tell", a retelling of the famous folk tale,
70 is nearly as brief but roams more widely in its use of Inform's
71 capabilities. Finally "Captain Fate" presents a comic-book hero in urgent
72 need of a change. By the end of the guide, we'll have touched on less than
73 half of Inform's capabilities, but we hope we'll have mentioned most of the
74 things that matter when you're starting out to design your first Inform
77 One final point: Inform is a powerful system, often offering several
78 different ways of tackling a particular design requirement. We've tried to
79 present things as simply and consistently as possible, but you shouldn't be
80 surprised to discover other approaches, maybe shorter, maybe more
81 efficient, than those shown here.
83 Presentation and style
84 ======================
86 Most of the guide's text appears in this typeface, except where we're using
87 words which are part of the Inform system (like ``print``, ``Include``,
88 ``VerbLib``) or are extracted from one of our games (like ``bird``,
89 ``nest``, ``top_of_tree``). Terms in **bold type** are included in the
90 glossary -- Appendix G on page 273. We switch to italic type for a
91 placeholder: for example you should read the Inform statement:
97 as meaning "display on the player's screen the arbitrary character or
98 characters which are represented here by the placeholder *string*".
99 Examples might include::
101 print "Hello world!";
102 print "Fourscore and seven years ago our fathers brought forth on
103 this continent a new nation, [...] and that government of
104 the people, by the people, for the people shall not perish
107 We place the "TYPE" symbol alongside game fragments which you can type in
108 as a part of our working examples. This differentiates them from other
109 code snippets whose only purpose is to illustrate some particular feature.
113 The "TYPE" symbol doesn't really work here. Think of a better way to
114 indicate typed-in fragments.
116 Useful Internet resources
117 =========================
119 One of our basic assumptions -- along with your burning desire to learn
120 Inform and your ability to work comfortably with the files and folders on
121 your computer -- is that you have access to the Internet. This is pretty
122 well essential, since almost everything you need is available only via this
123 medium. In particular, you'll find much helpful material at these
126 * http://www.inform-fiction.org/
128 The Inform home page, maintained by Graham Nelson and a small team of
129 helpers. Most important, this is where you can find the *Inform
130 Designer's Manual* in PDF format.
132 * http://mirror.ifarchive.org/
134 The IF Archive (or actually a high-speed mirror copy of it), from which
135 you can download almost anything that's free and in the public domain.
136 For a clickable map of Inform-related parts of the Archive, see
137 http://www.firthworks.com/roger/informfaq/hh.html.
141 Prior to August 2001, the IF Archive was located elsewhere, at
142 ftp://ftp.gmd.de/if-archive/, and references to that location can
143 still occasionally be found. *Do not use* the old location: any
144 information still available from there is likely to be out-of-date.
146 * http://www.firthworks.com/roger/
148 Roger Firth's Inform pages, including the Informary (what's new in
149 Inform?), and the Inform Frequently Asked Questions (FAQ) pages.
151 * http://www.plover.net/~textfire/raiffaq/
153 A more general list of FAQs about IF authorship, covering both Inform
154 and the other main systems.
156 * news:rec.arts.int-fiction
158 The Usenet newsgroup for authors of IF, commonly known by the
159 abbreviation RAIF. Here you'll find discussion on IF technology,
160 criticism and game design issues, and fast, friendly and knowledgeable
161 assistance with your own "how do I..." questions (but please, look in
164 * news:rec.games.int-fiction
166 The complementary newsgroup for IF *players*, often known as RGIF.
170 Update these links appropriately. The newsgroups in particular are
171 mostly unused these days.
176 Becoming sufficiently conversant with Inform to be able to share it with
177 others is not something done quickly or in isolation. In getting to where
178 we are today, we have been assisted at many times and in many ways by the
179 notably supportive and good-natured people, far too numerous to list by
180 name, who make ``rec.arts.int-fiction`` such an invaluable IF resource. We
181 are grateful to you all.
183 In creating this guide, we have received specific help from a number of
184 people. First and foremost we must mention Graham Nelson, who kindly wrote
185 the Foreword, and delighted us with long and detailed lists of helpful
186 comments and suggestions on two of our drafts; also Dennis G. Jerz, who
187 patiently and skilfully edited the text, making innumerable improvements to
188 our often wayward and inconsistent prose. David Cornelson supervised the
189 Second Edition's transformation into professionally printed respectability.
190 Further assistance came from Barney Firth, Christine Firth, Harry Firth,
191 Megan Firth, Jim Fisher, Rosemary Frezza, Phil Graham, Graham Holden, Paul
192 Johnson, Yoon Ha Lee, Brian Pylant, Jo Quinn, Milos Radovanovic, Muffy
193 St. Bernard, Gunther Schmidl, Emily Short, Curt Siffert, A. Sloe, Pavel
194 Soukenik, Elise Stone, Brent VanFossen and R. Cliff Young. Thank you: it
195 is impossible to overstate the value of this freely given support and
198 The drop capitals, and their associated poem, are from "A Picture
199 Alphabet", digitised from a collection of public domain woodcuts, circa
200 1834, by Steven J. Lundeen of emerald city fontwerks.
204 Reference to the drop-caps should only apply to those places they're
205 used (just the PDF?).
207 All credit to the generosity of http://briefcase.yahoo.com/ for making
208 international file-sharing such a breeze.
210 Finally, of course, we owe an enormous debt of gratitude to Graham Nelson
211 for devising it all, thereby giving us the opportunity -- first
212 independently and later in enjoyable collaboration -- of using, and
213 eventually of presenting, the Inform text adventure development system.
216 | *Wallingford, England*
223 .. rubric:: Footnotes
226 If you feel confused about IF in general or about this distinction
227 between writing and playing in particular, try glancing ahead at "Just
228 what is interactive fiction?" on page 13 and at "How to play an IF game"
229 on page 209; also, you may find the Ifaq at
230 http://www.plover.net/~textfire/raiffaq/ifaq/ helpful.