§A1   Library attributes

absent

A ‘floating object’ (one with a found_in property, which can appear in many different rooms) which is absent will in future no longer appear in the game. Note that you cannot make a floating object disappear merely by giving it absent, but must explicitly remove it as well.

animate

“Is alive (human or animal).” Can be spoken to in “richard, hello” style; matches the creature token in grammar; picks up “him” or “her” (according to gender) rather than “it”, likewise “his”; an object the player is changed into becomes animate; some messages read “on whom”, etc., instead of “on which”; can't be taken; its subobjects “belong to” it rather than “are part of” it; messages don't assume it can be “touched” or “squeezed” as an ordinary object can; the actions Attack, ThrowAt are diverted to life rather than rejected as being ‘futile violence’.

clothing

“Can be worn.”

concealed

“Concealed from view but present.” The player object has this; an object which was the player until ChangePlayer happened loses this property; a concealed door can't be entered; does not appear in room descriptions.

container

Affects scope and light; object lists recurse through it if open (or transparent); may be described as closed, open, locked, empty; a possession will give it a LetGo action if the player tries to remove it, or a Receive if something is put in; things can be taken or removed from it, or inserted into it, but only if it is open; likewise for “transfer” and “empty”; room descriptions describe using when_open or when_closed if given; if there is no defined description, an Examine causes the contents to be searched (i.e. written out) rather than a message “You see nothing special about…”; Search only reveals the contents of containers, otherwise saying “You find nothing”. Note: an object cannot be both a container and a supporter.

door

“Is a door or bridge.” Room descriptions describe using when_open or when_closed if given; and an Enter action becomes a Go action. If a Go has to go through this object, then: if concealed, the player “can't go that way”; if not open, then the player is told either that this cannot be ascended or descended (if the player tried “up” or “down”), or that it is in the way (otherwise); but if neither, then its door_to property is consulted to see where it leads; finally, if this is zero, then it is said to “lead nowhere” and otherwise the player actually moves to the location.

edible

“Can be eaten” (and thus removed from game).

enterable

Affects scope and light; only an enterable on the floor can be entered. If an enterable is also a container then it can only be entered or exited if it is open.

female

This object has a feminine name. In games written in English, this makes her a female person, though in other languages it might be inanimate. The parser uses this information when considering pronouns like “her”. (In English, anything animate is assumed to be male unless female or neuter is set.)

general

A general-purpose attribute, defined by the library but never looked at or altered by it. Available for designers to use if they choose to do so.

light

“Is giving off light.” (See §19.) Also: the parser understands “lit”, “lighted”, “unlit” using this; inventories will say “(providing light)” of it, and so will room descriptions if the current location is ordinarily dark; it will never be automatically put away into the player's SACK_OBJECT, as it might plausibly be inflammable or the main light source.

lockable

Can be locked or unlocked by a player holding its key object, which is given by the property with_key; if a container and also locked, may be called “locked” in inventories.

locked

Can't be opened. If a container and also lockable, may be called “locked” in inventories.

male

This object has a masculine name. In games written in English, this makes him a male person, though in other languages it might be inanimate. The parser uses this information when considering pronouns like “him”. (In English, anything animate is assumed to be male unless female or neuter is set.)

moved

“Has been or is being held by the player.” Objects (immediately) owned by the player after Initialise has run are given it; at the end of each turn, if an item is newly held by the player and is scored, it is given moved and OBJECT_SCORE points are awarded; an object's initial message only appears in room descriptions if it is unmoved.

neuter

This object's name is neither masculine nor feminine. (In English, anything without animate is assumed neuter, because only people and higher animals have gender. Anything animate is assumed male unless female or neuter is set. A robot, for instance, might be an animate object worth making neuter.)

on

“Switched on.” A switchable object with on is described by with_on in room descriptions; it will be called “switched on” by Examine.

open

“Open door or container.” Affects scope and light; lists (such as inventories) recurse through an open container; if a container, called “open” by some descriptions; things can be taken or removed from an open container; similarly inserted, transferred or emptied. A container can only be entered or exited if it is both enterable and open. An open door can be entered. Described by when_open in room descriptions.

openable

Can be opened or closed, unless locked.

pluralname

This single object's name is in the plural. For instance, an object called “seedless grapes” should have pluralname set. The library will then use the pronoun “them” and the indefinite article “some” automatically.

proper

Its short name is a proper noun, and never preceded by “the” or “The”. The player's object must have this (so something changed into will be given it).

scenery

Not listed by the library in room descriptions; “not portable” to be taken; “you are unable to” pull, push, or turn it.

scored

The player gets OBJECT_SCORE points for picking it up for the first time; or, if a room, ROOM_SCORE points for visiting it for the first time.

static

“Fixed in place” if player tries to take, remove, pull, push or turn.

supporter

“Things can be put on top of it.” Affects scope and light; object lists recurse through it; a possession will give it a LetGo action if the player tries to remove it, or a Receive if something is put in; things can be taken or removed from it, or put on it; likewise for transfers; a player inside it is said to be “on” rather than “in” it; room descriptions list its contents in separate paragraphs if it is itself listed. Note: an object cannot be both a container and a supporter.

switchable

Can be switched on or off; listed as such by Examine; described using when_on or when_off in room descriptions.

talkable

Player can talk to this object in “thing, do this” style. This is useful for microphones and the like, when animate is inappropriate.

transparent

“Contents are visible.” Affects scope and light; a transparent container is treated as if it were open for printing of contents.

visited

“Has been or is being visited by the player.” Given to a room immediately after a Look first happens there: if this room is scored then ROOM_SCORE points are awarded. Affects whether room descriptions are abbreviated or not.

workflag

Temporary flag used by Inform internals, also available to outside routines; can be used to select items for some lists printed by WriteListFrom.

worn

“Item of clothing being worn.” Should only be an object being immediately carried by player. Affects inventories; doesn't count towards the limit of MAX_CARRIED; won't be automatically put away into the SACK_OBJECT; a Drop action will cause a Disrobe action first; so will PutOn or Insert.

Note.   The only library attributes which it's useful to apply to locations are light, scored and visited.