, 2008. Crossword grids such as those appearing in most North American newspapers and
magazines consist mainly of solid regions of uninterrupted white squares, separated more sparsely by shaded squares. Every letter is "checked" (i.e., is part of both an "across" word and a "down" word) and usually each answer must contain at least three letters. In such puzzles shaded squares are typically limited to about one-sixth of the total. Crossword grids elsewhere, such as in Britain,
South Africa,
India and Australia, have a
lattice-like structure, with a higher percentage of shaded squares (around 25%), leaving about half the letters in an answer unchecked. For example, if the top row has an answer running all the way across, there will often be no across answers in the second row. Another tradition in puzzle design (in North America, India, and Britain particularly) is that the grid should have 180-degree
rotational symmetry, so that its pattern appears the same if the paper is turned upside down. Most puzzle designs also require that all white cells be orthogonally contiguous (that is, connected in one mass through shared sides, to form a single
polyomino). Substantial variants from the usual forms exist. Two of the common ones are barred crosswords, which use bold lines between squares (instead of shaded squares) to separate answers, and circular designs, with answers entered either radially or in concentric circles. "Free form" crosswords ("criss-cross" puzzles), which have simple, asymmetric designs, are often seen on school worksheets, children's menus, and other entertainment for children. Grids forming shapes other than squares are also occasionally used. Puzzles are often one of several standard sizes. For example, many weekday newspaper puzzles (such as the American
New York Times crossword puzzle) are 15×15 squares, while weekend puzzles may be 21×21, 23×23, or 25×25. The
New York Times puzzles also set a common pattern for American crosswords by increasing in difficulty throughout the week: their Monday puzzles are the easiest and the puzzles get harder each day until Saturday. Their larger Sunday puzzle is about the same level of difficulty as a weekday-size Thursday puzzle. This has led U.S. solvers to use the day of the week as a shorthand when describing how hard a puzzle is: e.g. an easy puzzle may be referred to as a "Monday" or a "Tuesday", a medium-difficulty puzzle as a "Wednesday", and a truly difficult puzzle as a "Saturday". Typically clues appear outside the grid, divided into an across list and a down list; the first cell of each entry contains a number referenced by the clue lists. For example, the answer to a clue labeled "17 Down" is entered with the first letter in the cell numbered "17", proceeding down from there. Numbers are almost never repeated; numbered cells are numbered consecutively, usually from left to right across each row, starting with the top row and proceeding downward. Some Japanese crosswords are numbered from top to bottom down each column, starting with the leftmost column and proceeding right.
Clues: conventions and types American-style crossword clues, called
straight or
quick clues by those more familiar with cryptic puzzles, are often simple definitions of the answers. Often, a straight clue is not in itself sufficient to distinguish between several possible answers, either because multiple synonymous answers may fit or because the clue itself is a homonym (e.g., "Lead" as in to be ahead in a contest or "Lead" as in the element), so the solver must make use of
checks to establish the correct answer with certainty. For example, the answer to the clue "PC key" for a three-letter answer could be
ESC,
ALT,
TAB,
DEL, or
INS, so until a
check is filled in, giving at least one of the letters, the correct answer cannot be determined. In most American-style crosswords, the majority of the clues in the puzzle are straight clues, with the remainder being one of the other types described below. Crossword clues are generally consistent with the solutions. For instance, clues and their solutions should always agree in tense, number, and degree. If a clue is in the past tense, so is the answer: thus "Traveled on horseback" would be a valid clue for the solution
RODE, but not for
RIDE. Similarly, "Family members" would be a valid clue for
AUNTS but not
UNCLE, while "More joyful" could clue
HAPPIER but not
HAPPIEST.
Capitalization Capitalization of answer letters is conventionally ignored; crossword puzzles are typically filled in, and their answer sheets published, in
all caps. This ensures a
proper name can have its initial
capital letter checked with a non-capitalizable letter in the intersecting clue. Some clue examples: • Fill-in-the-blank clues are often the easiest in a puzzle and a good place to start solving, e.g., "_____
Boleyn" =
ANNE. • A question mark at the end of clue usually signals that the clue/answer combination involves some sort of pun or wordplay, e.g., "Grateful?" =
ASHES, since a grate might be full of them. • Most widely distributed American crosswords today (e.g.,
The New York Times,
The Washington Post,
The Boston Globe,
USA Today, etc.) also contain colloquial answers, i.e., entries in the puzzle grid that try to replicate everyday colloquial language. In such a puzzle, one might see phrases such as
WHATS UP,
AS IF, or
WHADDYA WANT.
Abbreviations The constraints of the American-style grid (in which every letter is checked) often require a fair number of answers not to be dictionary words. As a result, the following ways to clue abbreviations and other non-words, although they can be found in "straight" British crosswords, are much more common in American ones: • Abbreviations, the use of a foreign language, variant spellings, or other unusual word tricks are indicated in the clue. A crossword creator might choose to clue the answer
SEN (as in the abbreviation for "senator") as "Washington bigwig: Abbr." or "Member of Cong.", with the abbreviation in the clue indicating that the answer is to be similarly abbreviated. The use of "Var." indicates the answer is a variant spelling (e.g.,
EMEER instead of
EMIR), while the use of foreign language or a foreign place name within the clue indicates that the answer is also in a foreign language. For example,
ETE (
été, French for "summer") might be clued as "Summer, in the
Sorbonne".
ROMA could be clued as "Italia's capital", whereas the clue "
Italy's capital" would indicate the English spelling
Rome. • The eight possible abbreviations for a
position on a compass, e.g.,
NNW (north-northwest) or
ESE (east-southeast), occur with some frequency. They can be clued as simply "Compass point", where the desired answer is determined by a combination of
logic—since the third letter can be only E or W, and the second letter can be only N or S—and a process of elimination using checks. Alternatively, compass point answers are more frequently clued as "XXX to YYY direction", where XXX and YYY are two place names. For example,
SSW might be clued as "New York to Washington DC dir.". Similarly, a clue such as "Right on the map" means
EAST. A clue could also consist of objects that point a direction, e.g., "
vane dir." or "
windsock dir.". •
Roman numerals, and arithmetic involving them, frequently appear as well; the clue "IV times III" (4×3) would yield
XII (12). • In addition, partial answers are allowed in American-style crosswords, where the answer represents part of a longer phrase. For example, the clue "Mind your _____ Qs" gives the answer
PSAND (Ps and). • Non-dictionary phrases are also allowed in answers. Thus, the clue "Mocked" could result in the grid entry
LAUGHED AT.
Themes Many American crossword puzzles feature a "theme" consisting of a number of long entries (generally three to five in a standard 15×15-square "weekday-size" puzzle) that share some relationship, type of pun, or other element in common. As an example, the
New York Times crossword of April 26, 2005 by Sarah Keller, edited by
Will Shortz, featured five themed entries ending in the different parts of a tree:
SQUARE ROOT,
TABLE LEAF,
WARDROBE TRUNK,
BRAIN STEM, and
BANK BRANCH. The above is an example of a category theme, where the theme elements are all members of the same set. Other types of themes include: • Quote themes, featuring a famous quote broken up into parts to fit in the grid (and usually clued as "Quote, part 1", "Quote, part 2", etc.) • Rebus themes, where multiple letters or even symbols occupy a single square in the puzzle (e.g.,
BERMUDAΔ) • Addition themes, where theme entries are created by adding a letter, letters, or word(s) to an existing word or phrase. For example, "Crucial pool shot?" =
CRITICAL MASSE (formed by taking the phrase "
critical mass" and adding an "e" on the end. All the theme entries in a given puzzle must be formed by the same process (so another entry might be "Greco-Roman buddy?" =
WRESTLING MATE—"wrestling mat" with an "e" added on). An example of a multiple-letter addition (and one that does not occur at the end of the entry) might be "Crazy about kitchen storage?" =
CABINET FEVER (derived from "
cabin fever"). • Subtraction themes, the reverse of the above, where letters are removed to make a new word or phrase. • Synonym themes, where the theme entries all contain synonyms, e.g., a
Los Angeles Times puzzle featuring a set of theme entries that contain the words
RAVEN,
JET,
EBONY, and
SABLE, all synonyms for "black". The
Simon & Schuster Crossword Puzzle Series has published many unusually themed crosswords. "Rosetta Stone", by Sam Bellotto Jr., incorporates a
Caesar cipher cryptogram as the theme; the key to breaking the cipher is the answer to 1Across. Another unusual theme requires the solver to use the answer to a clue as another clue. The answer to
that clue is the real solution.
Indirect clues Many puzzles feature clues involving wordplay which are to be taken metaphorically or in some sense other than their literal meaning, requiring some form of
lateral thinking. Depending on the puzzle creator or the editor, this might be represented either with a question mark at the end of the clue or with a modifier such as "maybe" or "perhaps". In more difficult puzzles, the indicator may be omitted, increasing ambiguity between a literal meaning and a wordplay meaning. Examples: • "Half a dance" could clue
CAN (half of
CANCAN) or
CHA (half of
CHACHA). • If taken literally, "Start of spring" could clue
MAR (for March), but it could also clue
ESS, the spelled-out form of the starting letter
S. • "Nice summer?" clues
ETE, summer in
Nice, France (
été being French for "summer"), rather than a nice (pleasant) summer. This clue also takes advantage of the fact that in American-style crosswords, the initial letter of a clue is always capitalized, whether or not it is a proper noun. In this clue, the initial capitalization further obscures whether the clue is referring to "nice" as in "pleasant" or "Nice" as in the French city. • "Pay addition", taken literally, clues
BONUS. When taken as an indirect clue, however, it could also clue
OLA (the
addition of
-ola to
pay- results in
PAYOLA).
Other clue variations Any type of puzzle may contain
cross-references, where the answer to one clue forms part of another clue, in which it is referred to by number and direction. E.g., a puzzle might have 1-across clued as "Central character in The Lord of the Rings" =
FRODO, with 17-down clued as "Precious object for 1-Across" =
RING. When an answer is composed of multiple or hyphenated words, some crosswords (especially in Britain) indicate the structure of the answer. For example, "(3,5)" after a clue indicates that the answer is composed of a three-letter word followed by a five-letter word. Most American-style crosswords do not provide this information.
Metapuzzles Some crossword designers have started including a metapuzzle, or "meta" for short, a second puzzle within the completed puzzle. After the player has correctly solved the crossword puzzle in the usual fashion, the solution forms the basis of a second puzzle. The designer usually includes a hint to the metapuzzle. For instance, the puzzle ''Eight Isn't Enough'' by Matt Gaffney gives the clue "This week's contest answer is a three-word phrase whose second word is 'or'." The crossword solution includes the entries "BROUGHT TO NAUGHT", "MIGHT MAKES RIGHT", "CAUGHT A STRAIGHT", and "HEIGHT AND WEIGHT", which are all three-word phrases with two words ending in -ght. The solution to the meta is a similar phrase in which the middle word is "or": "FIGHT OR FLIGHT". Since September 2015, the
Wall Street Journal Friday crossword has featured a crossword contest metapuzzle, with the prize of a WSJ mug going to a reader randomly chosen from among those submitting the correct answer.
Schrödinger or quantum puzzles Some puzzle grids contain more than one correct answer for the same set of clues. These are called Schrödinger or quantum puzzles, alluding to the
Schrödinger's Cat thought experiment in
quantum physics. Schrödinger puzzles have frequently been published in venues including
Fireball Crosswords and
The American Values Club Crosswords, and at least ten have appeared in
The New York Times since the late 1980s. The daily
New York Times puzzle for November 5, 1996, by
Jeremiah Farrell, had a clue for 39 across that read "Lead story in tomorrow's newspaper, with 43 Across (!)." The answer for 43 across was ELECTED; depending on the outcome of
that day's presidential election, the answer for 39 across would have been correct with either
CLINTON or
BOBDOLE, as would each of the corresponding down answers. On September 1, 2016, the daily
New York Times puzzle by Ben Tausig had four squares which led to correct answers reading both across and down if solvers entered either "M" or "F". The puzzle's theme,
GENDERFLUID, was revealed at 37 across in the center of the puzzle: "Having a variable identity, as suggested by four squares in this puzzle." == Cryptic crosswords ==