Jim Aikin - Inform 7 Handbook

Inform 7 Handbook

by Jim Aikin

version 2.0 (May 2015)

valid for 6L38

The Inform 7 Handbook is copyright (c) 2015 by Jim Aikin. The Inform 7 Handbook has been released under and is subject to the terms of the Creative Commons Public License, the terms of which are hereby incorporated by reference. Please see Appendix C of this book and read it before using this material. Your use of this material signifies your agreement to the terms of the License.

You are free to copy, distribute, and transmit this work, and you are free to excerpt and adapt it, in whole or in part, subject to the following conditions:

1) You must attribute the work by prominently displaying the words Inform 7 Handbook, by Jim Aikin.

2) You may not in any way suggest that Jim Aikin endorses you or your use of the Inform 7 Handbook.

3) You may not receive any monetary or other compensation for your copying, distribution, or transmission of this work, nor for any derivative work that incorporates it, in whole or in part.

4) If you alter, transform, or build upon this work, you may distribute the resulting work only under the same or similar license to this one.

5) For any reuse or distribution, you must make clear to others the license terms of this work by incorporating the text of the license (see Appendix C), or by including a link to a Web page wherein the license resides.

Table of Contents

Foreword 8

Acknowledgments 11

About the Author 11

Chapter 1: Getting Started 12

Downloading & Installing 14

The Inform 7 Program 14

The Page Headers 16

The Go! Button 20

The Release Button 22

Other Features 23

Using the Built-In Documentation 23

What Happens in a Game 24

Entering Commands 25

Downloading & Playing Games 29

Whats This .z8 Stuff All About, Anyway? 29

Writing Your First Game 31

From the Top 32

The Detail Trap 33

Title Trickery 33

Telling a Story 35

Managing Your Project(s) 35

About Inform Source Code 36

All About Bugs 36

Testing Your Game 38

Using the Debugging Commands 39

Another Way to Debug 41

Puzzles 43

Extensions for Inform 44

Where to Learn More 46

Chapter 2: Rooms & Scenery

Creating Your First Room 48

Scenery 51

The Names of Things 52

How Much Scenery Is Enough? 55

Distant Scenery 56

Adding More Rooms to the Map 58

The Great Outdoors 61

Enterable Scenery 64

Doors 65

Locked Doors 67

Secret Doors 69

Dangerous Doors 70

Travel by Fiat 71

Windows 71

You cant go that way. 72

Duplicate Exits & Twisty Connections 73

Hallways with Lots of Doors 75

Changing the Map During the Game 76

Regions 78

Backdrops 80

Removing a Backdrop 80

Dark Rooms 81

Backdrops in Dark Rooms 84

Seemingly Identical Rooms 84

Floorless Rooms 85

When Is a Room visited? 85

More About Room Descriptions 87

Chapter 3: Things 90

Creating Things 90

Things vs. Kinds 91

The Names of Things 93

Long Names 95

Initial Appearance 96

Adding Vocabulary Words with Understand 97

Conditional Vocabulary 98

Containers & Supporters 99

Stealthy Containers 104

Sneaky Supporters 108

Looking Under & Looking Behind 109

Take All 112

Enterable Containers & Supporters 112

Moving Things Around 114

Inventory 115

Testing Where a Thing Is 117

Things Can Have Properties 118

Number Properties 119

Word Properties 120

Plurals & Collective Objects 123

More about Collections & Kinds 125

Objects That Have Parts 128

Reading Matter 129

Writing on Things 130

Mechanical Marvels 132

Smelling & Listening 136

Transforming One Thing into Another 138

New Ways to Use Things 139

Holding Something Up in the Air 140

Tipping Something 141

Holding Something Against Something Else 142

Chapter 4: Actions 144

Built-In Actions 144

Using Instead 147

Action Processing 148

Rulebooks & Stop the Action 153

Three Types of Actions 155

Creating New Actions 156

[Any Thing] 160

Same Action, New Results 163

Redirecting an Action 163

Actions with Topics 165

Action Processing Summary 166

Chapter 5: Creating Characters 170

Overview 172

The Player Character 173

Creating an NPC 174

Mr. & Mrs. 177

Conversations, Part I: talk to 178

Conversations, Part II: ask/tell/give/show 180

Topics of Conversation 181

Conversations, Part III: Character Knowledge 184

Conversations, Part IV: Menu-Based Conversation 186

Giving Orders to Characters 186

Giving Orders that Involve Going Elsewhere 188

Moving Characters Around 189

Characters Who Follow the Player 192

Characters the Player Can Follow 193

Stage Business 194

Character Actions 195

Combat 196

Moods 198

Body Parts 199

Chapter 6: Puzzles 200

Mapping 201

Blocked Passageways 201

Darkness 202

Hidden Items 203

Items Out of Reach 204

Locked Containers 205

Combination Locks 205

Manipulation Difficulties 205

Enigmas 207

Deceptive Appearances & Unusual Usages 207

Assembly Required 208

Mechanisms 209

Vehicles 209

Consulting Information Sources 209

The Uncooperative Character 210

Timed Puzzles 210

Inadequate Implementation 211

Chapter 7: Winning & Losing 213

A Word About Fairness 214

Keeping Score 215

A Treasure Chest 216

Achievements 218

Chapter 8: Time & Scenes 220

Passing Time 220

Future Events 222

Scenes 223

Chaining Scenes 224

Using Scenes to Control Action 225

Every Turn Rules 228

Chapter 9: Phrasing & Punctuation 231

Types of Source Text 232

Text Insertions 233

Switchable Markup 237

Quotes Within Quotes 238

Breaking Up Paragraphs 239

Large Text Blocks 240

White Space 240

Objects vs. Rules 242

The Names of Things 244

Punctuation 245

Assertions 246

Values 247

Arithmetic 252

Doing Calculations 253

Testing Conditions 255

Creating New Phrases 256

Indenting 257

Too Many Indents 261

Headings 262

Loops 263

Chapter 10: Advanced Topics 265

Story Tense and Viewpoint 265

Code Optimization 265

Instead of Instead 266

Every Turn Rules 267

Other Ways to Streamline Your Code 268

Tables 268

The Skein 272

Using the Index 273

Replacing Rules in the Standard Library 274

Helping the Parser 275

Pronouns 276

Clearing the Screen 276

I6 Constants 277

Relations 278

Adding Hints 281

Special Features in Glulx 282

What Does Inform 6 Have to Do with Inform 7? 282

So, Is Inform 7 the Ultimate IF Programming Language? 283

Appendix A: Glossary 286

Appendix B: Updating Older Extensions 289

Appendix C: Short Sample Games 292

Flea Market 292

Mr Potato Head 294

A Dangerous Jewel Box 296

The Omega Machine 298

The Lurking Critter 300

Restraints 301

Broken Eggs 304

Indoors & Outdoors 306

Appendix D: License

Somebody once said that if you ask five poets to define poetry, youll get seven definitions. Im sure Im misquoting wildly the original version may not have been about poetry at all but the point should be clear. There are undoubtedly more good ways to explain the intricacies of the Inform 7 programming language than there are people who have written tutorials on the subject.