Kinds Index Table of all the kinds;   how arithmetic affects them; and   details of each kind in turn. What are kinds?  ; More about kinds of object  ; And kinds of value

value	default value	repeat	props	under
object [48]	north
room [4]	Cave
thing [32]	yourself
door	nothing
container [1]	treasure chest
vehicle	nothing
player's holdall	nothing
supporter	nothing
backdrop	nothing
person [8]	yourself
man	nothing
woman	nothing
animal	nothing
frog warrior [5]	frog commander
device	nothing
weapon [17]	your natural weapon
natural weapon [8]	your natural weapon
mace [2]	unwieldy mace
small frog spear [5]	small frog spear
dagger [1]	gilded dagger
health potion [3]	health potion
direction [12]	north
region	nothing
. . . . . . . . . . . .	. . . . . . . . . . . .	. . .	. . .	. . .
number	0
time	9:00 AM
truth state	false
text	""
indexed text	""
unicode character	unicode 32 (a space)
snippet	word 1 of command
stored action	waiting
scene [1]	Entire Game
command parser error [20]	didn't understand error
faction  [3]	friendly
combat state  [4]	at-Normal
use option	the ineffectual option
table name	a table with no rows or columns
equation name	an equation doing nothing
action name	waiting action
figure name [1]	Figure of cover
sound name	a silent non-sound
external file	a non-file
. . . . . . . . . . . .	. . . . . . . . . . . .	. . .	. . .	. . .
phrase K -> L	always the default value of L
relation of K	a relation never holding
K based rule producing L	the little-used do nothing rule
K based rulebook producing L	the action-processing rules
activity on K	printing the name
list of K	{ }
description of K	matching nothing
K valued property	--
K valued table column	--

The default value is used when we make something like a variable but don't tell Inform what its value is. For instance, if we write 'Zero hour is a time that varies', but don't tell Inform anything specific like 'Zero hour is 11:21 PM.', then Inform uses the value in the table above to decide what it will be. The same applies if we create a property (for instance, 'A person has a number called lucky number.'). Kinds of value not included in the table cannot be used in variables and properties.

A tick for repeat means that it's possible to repeat through values of this kind. For instance, 'repeat with T running through times:' is allowed, but 'repeat with N running through numbers:' is not - there are too many numbers for this to make sense. A tick here also means it's possible to form lists such as 'list of rulebooks', or to count the 'number of scenes'.

A tick for props means that values of this kind can have properties. For instance, 'A scene can be thrilling or dull.' makes an either/or property of a scene, but 'A number can be nice or nasty.' is not allowed because it would cost too much storage space. (Of course 'Definition:' can always be used to make adjectives applying to numbers; it's only properties which have storage worries.)

A tick for under means that it's possible to understand values of this kind. For instance, 'Understand "award [number]" as awarding.' might be allowed, if awarding were an action applying to a number, but 'Understand "run [rule]" as rule-running.' is not allowed - there are so many rules with such long names that Inform doesn't add them to its vocabulary during play.

Kinds of value marked with the calculator symbol are numerical - these are values we can add, multiply and so on. The range of these numbers depends on the Format setting for the project (Glulx format supports much higher numbers than Z-code).

object (plural objects)

Matches: value, sayable value
Objects are values intended to simulate physical things: places, people, things, and so on. They come in many kinds. The special value 'nothing' is also allowed, and can be used to mean 'no object at all'.
Usually singular-named not plural-named, improper-named not proper-named.
Can have printed name (text), printed plural name (text), indefinite article (text).

room (plural rooms) 

Represents geographical locations, both indoor and outdoor, which are not necessarily areas in a building. A player in one room is mostly unable to sense, or interact with, anything in a different room. Rooms are arranged in a map.
Usually lighted not dark, unvisited not visited.
Can have description (text), map region (object).

Cave , Small cavern , Grassy meadow , Troll lair 

thing (plural things)

Represents anything interactive in the model world that is not a room. People, pieces of scenery, furniture, doors and mislaid umbrellas might all be examples, and so might more surprising things like the sound of birdsong or a shaft of sunlight.
Usually unlit not lit, inedible not edible, portable not fixed in place, described not undescribed, unmarked for listing not marked for listing, mentioned not unmentioned, neuter, ordinarily enumerated not ambiguously plural.
Usually not scenery, wearable, pushable between rooms, handled.
Can have description (text), initial appearance (text), matching key (object).

 32 things

	yourself, your natural weapon  , unwieldy mace , goblin , goblin's mace , boots of expeditious retreat , frog commander , small frog spear , frog commander's natural weapon , limping frog warrior , small frog spear , limping frog warrior's natural weapon , stout frog warrior , small frog spear , stout frog warrior's natural weapon , old frog warrior , small frog spear , old frog warrior's natural weapon , bright green frog warrior , small frog spear , bright green frog warrior's natural weapon , shrine , health potion , health potion , health potion , treasure chest , gilded dagger , cloak of shadows , large troll , large troll's natural weapon , huge club , goblin's natural weapon

door (plural doors) 

Represents a conduit joining two rooms, most often a door or gate but sometimes a plank bridge, a slide or a hatchway. Usually visible and operable from both sides (for instance if you write 'The blue door is east of the Ballroom and west of the Garden.'), but sometimes only one-way (for instance if you write 'East of the Ballroom is the long slide. Through the long slide is the cellar.').
Always fixed in place not portable.
Usually closed not open, openable not unopenable, unlocked not locked.
Usually not lockable.
Never pushable between rooms.
Can have other side (object).

container (plural containers)

Represents something into which portable things can be put, such as a teachest or a handbag. Something with a really large immobile interior, such as the Albert Hall, had better be a room instead.
Usually opaque not transparent, open not closed, unopenable not openable, unlocked not locked.
Usually not enterable, lockable.
Can have carrying capacity (number).

treasure chest 

vehicle (plural vehicles) 

Represents a container large enough for a person to enter, and which can then move between rooms at the driver's instruction. (If a supporter is needed instead, try the extension Rideable Vehicles by Graham Nelson.)
Always enterable.
Usually fixed in place not portable.

player's holdall (plural player's holdalls) 

Represents a container which the player can carry around as a sort of rucksack, into which spare items are automatically stowed away.
Always portable not fixed in place.
Usually openable not unopenable.

supporter (plural supporters)

Represents a surface on which things can be placed, such as a table.
Usually fixed in place not portable.
Usually not enterable.
Can have carrying capacity (number).

backdrop (plural backdrops) 

Represents an aspect of the landscape or architecture which extends across more than one room: for instance, a stream, the sky or a long carpet.
Always fixed in place not portable.
Usually scenery.
Never pushable between rooms.

person (plural people) 

Despite the name, not necessarily a human being, but anything animate enough to envisage having a conversation with, or bartering with.
Usually male not female, not at parry not at parry, not at dodge not at dodge, not retreater not retreater, not adrinking not adrinking, not shadowed not shadowed.
Usually not neuter.
Can have carrying capacity (number), health (number), permanent health (number), melee (number), defence (number), provoker (person), provocation (action name), initiative (number), concentration (number), combat AI rulebook (rulebook), faction (faction), combat state (combat state).

yourself, goblin , frog commander , limping frog warrior , stout frog warrior , old frog warrior , bright green frog warrior , large troll 

man (plural men)

Represents a man or boy.
Always male not female.
Never neuter.

woman (plural women)

Represents a woman or girl.
Always female not male.
Never neuter.

animal (plural animals)

Represents an animal, or at any rate a non-human living creature reasonably large and possible to interact with: a giant Venus fly-trap might qualify, but not a patch of lichen.

frog warrior (plural frog warriors) 

frog commander , limping frog warrior , stout frog warrior , old frog warrior , bright green frog warrior 

device (plural devices) 

Represents a machine or contrivance of some kind which can be switched on or off.
Usually switched off not switched on.

weapon (plural weapons) 

Usually not readied not readied.
Can have damage die (number), dodgability (number), passive parry max (number), active parry max (number), weapon attack bonus (number), maximum shots (number), current shots (number), maximum load time (number), current load time (number), shots text (text), reload text (text), reload stem text (text), out of ammo text (text).

 17 weapons

	your natural weapon  , unwieldy mace , goblin's mace , small frog spear , frog commander's natural weapon , small frog spear , limping frog warrior's natural weapon , small frog spear , stout frog warrior's natural weapon , small frog spear , old frog warrior's natural weapon , small frog spear , bright green frog warrior's natural weapon , gilded dagger , large troll's natural weapon , huge club , goblin's natural weapon

natural weapon (plural natural weapons) 

your natural weapon  , frog commander's natural weapon , limping frog warrior's natural weapon , stout frog warrior's natural weapon , old frog warrior's natural weapon , bright green frog warrior's natural weapon , large troll's natural weapon , goblin's natural weapon 

mace (plural maces) 

unwieldy mace , goblin's mace 

small frog spear (plural small frog spears) 

small frog spear , small frog spear , small frog spear , small frog spear , small frog spear 

dagger (plural daggers) 

gilded dagger 

health potion (plural health potions) 

health potion , health potion , health potion 

direction (plural directions) 

Represents a direction of movement, such as northeast or down. They always occur in opposite, matched pairs: northeast and southwest, for instance; down and up.
Usually unmarked for listing not marked for listing.
Can have opposite (direction).

 12 directions

	north, northeast, northwest, south, southeast, southwest, east, west, up, down, inside, outside

region (plural regions) 

Represents a broader area than a single room, and allows rules to apply to a whole geographical territory. Each region can contain many rooms, and regions can even be inside each other, though they cannot otherwise overlap. For instance, the room Place d'Italie might be inside the region 13th Arrondissement, which in turn is inside the region Paris. Regions are useful mainly when the world is a large one, and are optional.

number (plural numbers) 

Matches: value, arithmetic value, sayable value
Whole number in the range -32768, -32767, ..., -2, -1, 0, 1, 2, 3, ..., 32767: small numbers can be written textually as 'one', 'two', 'three', ..., 'ten', 'eleven', 'twelve'. (A much larger number range is allowed if we compile the source to Glulx rather than the Z-machine: see the Settings panel.)

time (plural times) 

Matches: value, arithmetic value, sayable value
A time of day, written in the form '2:34 AM' or '12:51 PM', or a length of time such as '10 minutes' or '3 hours 31 minutes', which must be between 0 minutes and 23 hours 59 minutes inclusive.

truth state (plural truth states) 

Matches: value, sayable value
The state of whether something is 'true' or 'false'. (In other computing languages, this might be called 'boolean', after the 19th-century logician George Boole, who first realised this was a kind of value.)

text (plural texts)

Matches: value, sayable value
Some text in double quotation marks, perhaps with substitutions written in square brackets.

indexed text (plural indexed texts) 

Matches: value, sayable value
A flexible-length form of text which can be internally altered and searched. Inform automatically changes text to this format when necessary.

unicode character (plural unicode characters)

Matches: value, sayable value
A single character - a letter or item of punctuation.

snippet (plural snippets) 

Matches: value, sayable value
A fragment of the player's most recent typed command, taking in a run of consecutive words.

stored action (plural stored actions) 

Matches: value, sayable value
A stored action, which can later be tried.

scene (plural scenes) 

Matches: value, enumerated value, sayable value
Like a scene in a play: a period of time which is usually tied to events in the plot. Scenes are created by sentences like 'Midnight Arrival is a scene.'
Usually non-recurring not recurring.
Can have description (text).

Entire Game

command parser error (plural command parser errors)

Matches: value, enumerated value, sayable value

 20 command parser errors

	didn't understand error, only understood as far as error, didn't understand that number error, can only do that to something animate error, can't see any such thing error, said too little error, aren't holding that error, can't use multiple objects error, can only use multiple objects error, not sure what it refers to error, excepted something not included error, not a verb I recognise error, not something you need to refer to error, can't see it at the moment error, didn't understand the way that finished error, not enough of those available error, nothing to do error, noun did not make sense in that context error, referred to a determination of scope error, I beg your pardon error

faction  (plural factions)

Matches: value, enumerated value, sayable value

friendly  , passive  , hostile 

combat state  (plural combat states)

Matches: value, enumerated value, sayable value

at-Normal  , at-Act  , at-React  , at-Reacted 

use option (plural use options)

Matches: value, sayable value
One of the optional ways to configure Inform, such as the 'authorial modesty option'.

table name (plural table names) 

Matches: value, sayable value
Like tables of information in a book or newspaper, tables in Inform hold values which have been organised into rows and columns. A table name is just a single value, identifying which table is meant - say, 'Table of US Presidents' might be a table name value.

equation name (plural equation names)

Matches: value
Like formulae in a textbook or a scientific paper, equations in Inform are written out in displayed form and given names.

action name (plural action names) 

Matches: value, sayable value
An action is what happens when one of the people in the simulated world decides to do something. A full action would be something like 'dropping the box', but an action name is just the choice of which sort of thing is being done: here, it's 'the dropping action'. (Action names are always written with the word 'action' at the end, to make sure they aren't mistaken for full actions.)

figure name (plural figure names) 

Matches: value, enumerated value, sayable value
When made with the Glulx setting, an Inform project can include images as well as words, and these are called figures. A figure name is just the name of one of the figures in the current project.

Figure of cover

sound name (plural sound names) 

Matches: value, enumerated value, sayable value
When made with the Glulx setting, an Inform project can include sound effects or pieces of music. A sound name is just the name of one of these sounds in the current project.

external file (plural external files) 

Matches: value, enumerated value, sayable value
When made with the Glulx setting, an Inform project can make limited use of files stored on the computer which is operating the story at run-time. An external-file is just the name of one of these files (not the filename in the usual sense, but a name given to it in the Inform source text).

phrase K -> L (plural phrases K -> L)

contravariant in K, covariant in L 

Matches: value, sayable value

relation of K (plural relations of K)

covariant 

Matches: value, sayable value

K based rule producing L (plural K based rules producing L) 

contravariant in K, covariant in L 

Matches: value, sayable value
One of many, many rules which determine what happens during play. Rules can be triggered by scenes beginning or ending, by certain actions, at certain times, or in the course of carrying out certain activities.

K based rulebook producing L (plural K based rulebooks producing L) 

contravariant in K, covariant in L 

Matches: value, sayable value
A list of rules to follow, in sequence, to get something done. A rulebook is like a ring-binder, with the individual rules as sheets of paper. Inform normally sorts these into their 'natural' order, with the most specific rules first, but it's easy to shuffle the pages if you need to. When some task is carried out during play, Inform is normally working through a rulebook, turning the pages one by one.

activity on K (plural activities on K) 

contravariant 

Matches: value
An activity is something which Inform does as part of the mechanics of play - for instance, printing the name of an object, which Inform often has to do. An activity can happen by itself ('printing the banner text', for instance) or can be applied to an object ('printing the name of something', say).

list of K (plural lists of K) 

covariant 

Matches: value, sayable value
A flexible-length list of values, where all of the items have to have the same kind of value as each other - for instance, a list of rooms, or a list of lists of numbers. The empty list, with no items yet, is written { }, and a list with items in is written with commas dividing them - say {2, 5, 9}.

description of K (plural descriptions of K) 

covariant 

Matches: value
A description of a set of values, where all of the items have to have the same kind of value as each other - for instance, 'even numbers' or 'open doors which are in lighted rooms'.

K valued property (plural K valued properties)

covariant 

Matches: value

K valued table column (plural K valued table columns)

covariant 

Matches: value

Covariance means that if K is a kind of L, then something you make from K can be used as the same thing made from L. For example, a list of doors can be used as a list of things, because 'list of K' is covariant. Contravariance means it works the other way round. For example, an activity on things can be used as an activity on doors, but not vice versa, because 'activity of K' is contravariant.