TABLE 1A: GENERAL OPERATORS

Lvl	Operator	Placed	Asc	Purpose
0	,	between	left	separating values to work out
1	=	between	right	set equal to
5	+	between	left	16-bit signed addition
	-	between	left	16-bit signed subtraction
6	*	between	left	16-bit signed multiplication
	/	between	left	16-bit signed integer division
	%	between	left	16-bit signed remainder
	&	between	left	bitwise AND
	|	between	left	bitwise OR
	~	before		bitwise NOT
7	->	between	left	byte array entry
	-->	between	left	word array entry
8	-	before		16-bit signed negation
9	++	before		add 1 to then read
	++	after		read then add 1 to
	--	before		subtract 1 from then read
	--	after		read then subtract 1 from
10	.&	between	left	property array
	.#	between	left	property array size
11	(...)	after		routine call
12	.	between	left	property value
13	::	between	left	“superclass” operator

• “Lvl” refers to precedence level: thus *, on level 6, binds more tightly than +, down on level 5, so that 1+2*3 means 1+(2*3).
• - is “left associative”, so a-b-c means (a-b)-c. = is “right associative”, so v1=v2=7 means v1=(v2=7), setting both variables equal to 7.
• Although the table of operators has been divided over two pages, conditions and expressions can be freely mixed. When a condition is used as a value, it is always true (1) or false (0). When a value is used as a condition, any non-zero value is considered true, and only zero is considered false.

TABLE 1B: CONDITION OPERATORS

Lvl	Operator	Placed	Asc	Purpose
2	&&	between	left	one condition AND another
	||	between	left	one condition OR another
	~~	before		this condition NOT true
3	==	between	none	equal to?
	~=	between	none	not equal to?
	>	between	none	greater than?
	>=	between	none	greater than or equal to?
	<	between	none	less than?
	<=	between	none	less than or equal to?
	has	between	none	object has this attribute?
	hasnt	between	none	object hasn't this attribute?
	in	between	none	first obj a child of second?
	notin	between	none	first obj not a child of second?
	ofclass	between	none	obj inherits from class?
	provides	between	none	obj provides this property?
4	or	between	left	separating alternative values

• Conditions have no associativity and if you type a==b==c then Inform will ask you to add brackets for clarity.
• In the condition (C1 && C2), Inform decides on C1 first: if C1 is false then C2 is never considered at all. Similarly, if C1 is true then (C1 || C2) must be true and C2 is never considered.

TABLE 2A: LOWER ZSCII CHARACTER SET

	+0	+1	+2	+3	+4	+5	+6	+7
0
8	del	tab		em		new
16
24								esc
32	sp	!	"	#	$	%	&	'
40	(	)	*	+	,	-	.	/
48	0	1	2	3	4	5	6	7
56	8	9	:	;	<	=	>	?
64	@	A	B	C	D	E	F	G
72	H	I	J	K	L	M	N	O
80	P	Q	R	S	T	U	V	W
88	X	Y	Z	[	\	]	^	_
96	`	a	b	c	d	e	f	g
104	h	i	j	k	l	m	n	o
112	p	q	r	s	t	u	v	w
120	x	y	z	{	|	}	~

• To convert a character to a ZSCII value, add the numbers in the same row and column. For instance, the Inform constant 'J' is 72 plus 2 equals 74.
• Blank boxes indicate that no character exists with that value. The value will never be read from the keyboard and it is an error to try to print (char) it.
• Italicised entries can be read from the keyboard but not printed.
• “em” (an em-space) and “tab” (a tab-skip) are print-only, and only available if Inform is compiling a Version 6 game.
• ZSCII does not (normally) have “smart quotes”, that is, different characters for opening and closing quotations “ and ”. Some interpreters automatically smarten them when printed, though. And ZSCII does have «French» and »German« quotation marks (see table 2B).

TABLE 2B: HIGHER ZSCII CHARACTER SET

	+0	+1	+2	+3	+4	+5	+6	+7
128		↑	↓	←	→	f1	f2	f3
136	f4	f5	f6	f7	f8	f9	f10	f11
144	f12	k0	k1	k2	k3	k4	k5	k6
152	k7	k8	k9	ä	ö	ü	Ä	Ö
				@:a	@:o	@:u	@:A	@:O
160	Ü	ß	»	«	ë	ï	ÿ	Ë
	@:U	@ss	@>>	@<<	@:e	@:i	@:y	@:E
168	Ï	á	é	í	ó	ú	ý	Á
	@:I	@'a	@'e	@'i	@'o	@'u	@'y	@'A
176	É	Í	Ó	Ú	Ý	à	è	ì
	@'E	@'I	@'O	@'U	@'Y	@`a	@`e	@`i
184	ò	ù	À	È	Ì	Ò	Ù	â
	@`o	@`u	@`A	@`E	@`I	@`O	@`U	@^a
192	ê	î	ô	û	Â	Ê	Î	Ô
	@^e	@^i	@^o	@^u	@^A	@^E	@^I	@^O
200	Û	å	Å	ø	Ø	ã	ñ	õ
	@^U	@oa	@oA	@\o	@\O	@~a	@~n	@~o
208	Ã	Ñ	Õ	æ	Æ	ç	Ç	þ
	@~A	@~N	@~O	@ae	@AE	@,c	@,C	@th
216	ð	Þ	Ð	£	œ	Œ	¡	¿
	@et	@Th	@Et	@LL	@oe	@OE	@!!	@??
224
232
240
248					men	dbl	clk

• The cursor keys, function keys, numeric keypad keys and mouse clicks (menu click, double click, single click) are read-only. Mouse support is available only to a Version 6 game.
• The given escape-character sequences can be typed into source code. For instance print "@AEsop"; prints “Æsop”.
• “Eth” Ð and “Th(orn)” Þ are Icelandic characters.
• Characters 155 to 251 are configurable using the directive Zcharacter, which can in principle move any Unicode character in. See §36.

TABLE 3: COMMAND LINE SWITCHES

Sw	To	Meaning
-d*	0 to 2	contract double spaces: never (0), after full stops (1), after full stops, exclamation and question marks (2)
-e	off/on	economise by using the declared abbreviations
-g*	0 to 2	traces calls: none (0), all outside libraries (1), all (2)
-i	off/on	ignore default switches set within the file
-k	off/on	output Infix debugging information (and switch -D on)
-r	off/on	record all the text to a transcript file
-v*	3 to 8	compile to this Version of story file (default 5)
-C*	0 to 9	source is ASCII (0), or ISO 8859-1 to -9 (default 1)
-D	off/on	automatically include library's debugging features
-F*	0 or 1	use temporary files to reduce memory consumption
-M	off/on	compile as a Module for future linking
-S	on/off	compile strict error-checking at run-time (on by default)
-U	off/on	link in precompiled library modules
-X	off/on	include the Infix debugger
-a	off/on	trace assembly-language (without hex dumps; see -t)
-c	off/on	more concise error messages
-f	off/on	frequencies mode: show how useful abbreviations are
-h*	on/1/2	print help information: on filenaming (1), switches (2)
-j	off/on	list objects as constructed
-l	off/on	list every statement run through Inform
-m	off/on	say how much memory has been allocated
-n	off/on	print numbers of properties, attributes and actions
-o	off/on	print offset addresses
-p	off/on	give percentage breakdown of story file
-q	off/on	keep quiet about obsolete usages
-s	off/on	give statistics
-t	off/on	trace assembly-language (with full hex dumps; see -a)
-u	off/on	work out most useful abbreviations (very very slowly)
-w	off/on	disable warning messages
-x	off/on	print a hash # for every 100 lines compiled
-y	off/on	trace linking system
-z	off/on	print memory map of the Z-machine
-E*	0, 1, 2	errors in Acorn (0), Microsoft (1) or Mac (2) style

• The lower group has no effect except on what is printed out.
• The * stands for a decimal digit, 0 to 9. You can also clear any switch with a tilde, so -~x turns -x off.

TABLE 4: STATEMENTS

box ‹line-1› ‹line-2› … ‹line-n›
break
continue
do ‹code block› until ‹condition›
font on or off
for (‹initial code› : ‹condition to carry on› : ‹update code›) ‹code block›
give ‹object› ‹attribute-1› … ‹attribute-n›
if ‹condition› ‹code block›
if ‹condition› ‹code block› else ‹code-block›
jump ‹label›
move ‹object› to ‹destination›
new_line
objectloop ‹condition choosing objects› ‹code block›
print ‹list of printing specifications›
print_ret ‹list of printing specifications›
remove ‹object›
return ‹optional value›
rfalse
rtrue
spaces ‹number of spaces to print›
string ‹number› ‹text›
style roman or bold or underline or reverse or fixed
switch (‹value›) ‹block of cases … default: …›
while ‹condition› ‹code-block›

• Statements must be given in lower case.
• A statement beginning with a double-quoted string instead of a keyword like if is taken as a print_ret statement.
• Code blocks consist of either a single statement or a group of statements enclosed in braces { and }.
• The following low-level statements should not be used for Inform games:

  inversion
quit
read ‹text-buffer› ‹parsing-buffer›
  restore ‹label›
  save ‹label›

TABLE 5: DIRECTIVES

Abbreviate ‹word-1› … ‹word-n›
Array ‹new-name› ‹type› ‹initial values›
Attribute ‹new-name›
Class ‹new-name› ‹body of definition›
Constant ‹new-name› = ‹value›
Default ‹possibly-new-name›
End
Endif
Extend ‹grammar extension›
Global ‹new-name› = ‹value›
Ifdef ‹symbol-name›
Ifndef ‹symbol-name›
Ifnot
Iftrue ‹condition›
Iffalse ‹condition›
Import ‹list of imported goods›
Include ‹source code filename›
Link ‹module filename›
Lowstring ‹text›
Message ‹message-type› ‹diagnostic-message›
Object ‹header› ‹body of definition›
Property ‹new-name›
Release ‹number›
Replace ‹routine-name›
Serial "‹serial number›"
Switches ‹list of switches›
Statusline score or time
System_file
Verb ‹verb-definition›
Zcharacter etc.

• Nearby is an obsolete abbreviation for Object ->, now deprecated. A few other directives, Dictionary, Fake_action, Ifv3, Ifv5, Stub, Trace and Version, are either also obsolete or for compiler maintenance only.

TABLE 6A: ACTIONS PROVIDED BY THE LIBRARY: GROUP 1

Action	Typically produced by	Notes
Pronouns	“pronouns”	lists settings of “it” and so on
Quit	“quit”
Restart	“restart”
Restore	“restore”
Save	“save”
Verify	“verify”	checks story file integrity
ScriptOn	“script on”
ScriptOff	“script off”
NotifyOn	“notify on”	score change notification on
NotifyOff	“notify off”	and off
Places	“places”	list places visited
Objects	“objects”	list objects moved
Score	“score”
FullScore	“fullscore”	full breakdown of score
Version	“version”	prints version numbers
LMode1	“brief”	normal room descriptions
LMode2	“verbose”	always full room descriptions
LMode3	“superbrief”	always abbreviated

• A number of other group 1 actions are present in a game compiled with the -D “Debugging” switch. These actions come and go with different library releases and their presence shouldn't be relied on. See the library's “Grammar” file to see the current set.
• The library also defines four fake actions which have nothing to do with the world model. TheSame and PluralFound are defined by the parser as ways for the program to communicate with it. Miscellany and Prompt are defined as slots for LibraryMessages.

TABLE 6B: ACTIONS PROVIDED BY THE LIBRARY: GROUP 2

Action	Typically produced by	Notes
Look	“look”
Examine	“examine fish”
Search	“look inside cup”
Inv	“inventory”
InvTall	“inventory tall”	becomes Inv
InvWide	“inventory wide”	becomes Inv
Take	“take fish”	KS
Drop	“drop fish”	KS
Remove	“take dice from cup”	KS
PutOn	“put cup on board”	KS
Insert	“put dice in cup”	KS
LetGo	fake	caused by Remove
Receive	fake	caused by PutOn and Insert
Empty	“empty sack”	becomes EmptyT d_obj
EmptyT	“empty bag on box”	for each item inside, becomes
		Remove then Drop/PutOn/Insert
Transfer	“transfer egg to box”	becomes Drop/PutOn/Insert
Go	“north”	KS   special rules apply: see §15
Enter	“enter cage”	KS   can become Go if into a door
GetOff	“get off table”	KS
GoIn	“enter”	becomes Go in_obj
Exit	“exit”	KS   can become Go out_obj
Unlock	“unlock door”	KS
Lock	“lock door”	KS
SwitchOn	“switch radio on”	KS
SwitchOff	“switch radio off”	KS
Open	“open door”	KS
Close	“close door”	KS
Disrobe	“take hat off”	KS
Wear	“wear hat”	KS
Eat	“eat fish”	KS
Wait	“wait”

• Actions marked KS run “silently” when the library's variable keep_silent is set true. This means that if successful they print nothing: if unsuccessful, however, they print text as normal.
• Look and Examine actions send after messages after printing descriptions. Search sends after when the search is known to be possible but before the result is printed.

TABLE 6C: ACTIONS PROVIDED BY THE LIBRARY: GROUP 3

Action	Typically produced by	Notes
LookUnder	“look under doormat”
Listen	“listen [to tape]”	noun can be nothing
Taste	“taste marinade”
Touch	“touch paint”
Pull	“pull trolley”
Push	“push trolley”
Wave	“wave wand”
Turn	“turn dial”
PushDir	“push trolley north”	special rules apply: see §15
ThrowAt	“throw dart at board”
ThrownAt	fake	caused by ThrowAt
JumpOver	“jump over fence”
Tie	“tie rope [to hook]”	second can be nothing
Drink	“drink absinthe”
Fill	“fill bottle”
Attack	“fight soldiers”
Swing	“swing on rope”
Blow	“blow pipe”
Rub	“clean table”
Set	“set trap”
SetTo	“set timer to 10”	second not an object
Buy	“buy ice cream”
Climb	“climb ladder”
Squeeze	“squash tomato”
Burn	“burn papers [with match]”	second can be nothing
Dig	“dig lawn [with spade]”	second can be nothing
Cut	“cut paper”
Consult	“look up fish in book”	sets noun and the topic
Tell	“tell jemima about austin”	sets noun and the topic
Answer	“say confirmed to avon”	sets noun and the topic
Ask	“ask jemima about isaac”	sets noun and the topic
Give	“give coin to troll”
Show	“show pass to guard”
AskFor	“ask jemima for daisies”
WakeOther	“wake sleeper”
Kiss	“kiss jemima”
Sleep	“sleep”
Sing	“sing”
WaveHands	“wave”	see also Wave
Swim	“swim”, “dive”
Sorry	“sorry”
Strong	very rude words
Mild	fairly rude words
Jump	“jump”	see also JumpOver
Think	“think”
Smell	“smell coffee”	noun can be nothing
Pray	“pray”
VagueGo	“go”
Yes	“yes”
No	“no”
Wake	“wake up”	see also WakeOther

TABLE 6D: ACTIONS SENT TO LIFE RULES

Action	Typically produced by
Answer	“say yes to cashier”
Ask	“ask woman about plutonium”
Attack	“fight soldiers”
Give	“give coin to charon”
Kiss	“kiss jemima”
Order	“thorin, go west”
Show	“show pass to benton”
Tell	“tell paris about helen”
ThrowAt	“throw axe at dwarf”
WakeOther	“wake beauty up”