Solving crossword puzzles can improve vocabulary, exercise the mind, and develop problem-solving skills. Naturally, you might be wondering what the rules are for crossword puzzles, and we have described the most common rules associated with crosswords below.Crossword puzzlescan be solved by individuals or as a group. They are a great way to exercise the mind, improve vocabulary, and develop problem-solving skills. By following these simple rules, players can have fun and challenge themselves while solving crossword puzzles.
Basic Crossword Construction Rules
There are generally no hard-and-fast rules when it comes to crosswords, but the following is a shortlist of best practices that constructors of crossword puzzles abide by.
An In-depth Look at Crossword Rules
Major crossword outlets – such asThe New York Times,The New Yorker,Los Angeles Times, and others – follow a consistent set of construction standards. These rules govern the size and symmetry of the grid, word count limits, placement of black squares, thematic requirements, and the overall quality of the fill and clues.
Grid Size and Symmetry Requirements
Most daily crosswords use a standard 15×15 grid (15 rows by 15 columns), while Sunday puzzles are larger (commonly 21×21). The New York Times and Los Angeles Times, for example, adhere to these dimensions for weekdays and Sundays, respectively. Other sizes are occasionally used only if a theme necessitates it – for instance, editors may accept 16×15 or 15×16 grids (or similarly 14×15) when a theme-specific reason justifies the unusual size. However, anything larger than 15×15 is not accommodated on a regular weekday, and 21×21 is the upper limit for standard Sundays.
All major publishers require grid symmetry in the pattern of black squares. The dominant convention is 180° rotational symmetry, meaning the grid appears identical if rotated upside-down. In practice, if a black square is at the third cell of the first row, another will be at the third cell of the last row, and so on. Mirror symmetry (reflecting across a central vertical or horizontal axis) is occasionally accepted if a particular theme requires it. Truly asymmetrical grids are extremely rare and only allowed when a very unusual theme or gimmick demands breaking symmetry. For example, a puzzle with a highly irregular theme layout might drop the symmetry rule, but this is done sparingly and only with editorial approval. (The New York Times has published a few asymmetrical puzzles for special themes, and theNew Yorkeronce experimented with diagonal symmetry in a themeless puzzle.) It’s worth noting that some newer venues have relaxed the symmetry rule – for instance, the USA Today puzzle doesnotrequire symmetry at all – but the NYT, New Yorker, LA Times, Wall Street Journal, and most others stick to symmetrical grids.
IGrids historically are an odd number of cells on each side (e.g. 15, 21). This ensures there is a central cell that remains symmetrical onto itself when rotated. While not an absolute requirement (as 16×15 puzzles do exist), the vast majority of crossword grids use odd dimensions to facilitate symmetry.
Word Count Limits for Different Puzzle Sizes
Editors impose limits on the number of answers (words) in a puzzle’s fill. For a standard 15×15 daily crossword, the maximum word count is usually 78 entries for a themed puzzle. If the puzzle is themeless (often the case for the hardest puzzles of the week), an even lower cap applies – 72 words maximum for a 15×15 with no theme. These numbers are indeed the official NYT limits (78 for themed weekday, 72 for Fri/Sat themeless) and are echoed by the LA Times (which also uses 78 as the upper bound for 15×15 puzzles, dropping to 72 for a themeless). The rationale is that themeless puzzles should have wide-open white space, hence fewer but longer words, whereas a themed puzzle may need a few extra short words to accommodate theme entries.
For Sunday (21×21) puzzles, the word count naturally is higher but still limited. The New York Times caps Sundays at 140 words or fewer, and the LA Times similarly allows up to 144 words in a 21×21 grid. (A typical published Sunday crossword often has 136–140 words.) These caps keep puzzles from being overfilled with too many short entries and ensure a good balance of longer answers. Other sizes have proportional limits; for example, a 16×15 grid, being one row larger, might allow up to 81 words in the LA Times. In general, more cells allow more words, but editors maintain control so that grids aren’t overly choppy or filled with only short answers.
It’s also an unwritten rule that constructors strive to stay wellunderthe maximum word count when possible, especially for themeless puzzles. A lower word count (e.g. 68-70 entries in a 15×15) is associated with higher difficulty and wide-open grid design. For instance, aNew Yorkerthemeless may deliberately use only ~70–72 words to create a challenging, open puzzle. But regardless of the exact count, publishers willnot acceptpuzzles that exceed their stated maximums, as that would indicate too many short words or an overly easy construction.
No matter the size, puzzles cannot have any two-letter answers, which effectively sets a floor on word count as well. Every entry must be at least 3 letters long. This rule is universal across major publications and prevents excessively easy fill or trivial words.
Use of Black Squares and Grid Connectivity
Black squares (also called blocks) serve to separate words in the grid, and their placement is carefully regulated. No more than about 15–16% of the grid can be black squares under traditional rules. In a 15×15 grid (225 cells), this historically meant roughly 36 black squares maximum. Modern editors don’t always enforce a strict percentage, but they do have practical limits. For example, the LA Times explicitly sets a maximum of 43 black squares in a 15×15 puzzle. In practice, most 15×15 puzzles use around 30–38 black squares; using significantly more would crowd the grid with blocks and shorten the answers too much. Editors strongly discourage large clumps of black squares or “stacked” blocks that make a section of the puzzle empty. Every black square should ideally have a purpose (usually to facilitate the placement of theme answers or to achieve a smooth fill). “Cheater” squares – black squares added not to reduce word count but just to make constructing easier (for instance, placing a black square that doesn’t change the number of answers, only the length of some answers) – are allowed only sparingly. Overuse of such cheater blocks is viewed as inelegant, so constructors try to minimize them.
Every white cell must be fully checked, meaning it is part of both an Across word and a Down word. There can be no “unchecked” letters that only belong to one answer. This ensures fairness: a solver should always have a chance to get a letter from either the across or down clue intersecting it. All major outlets enforce this – you will not see a letter that isn’t crossed by another word in an NYT or LA Times puzzle. Similarly, the grid must be fully connected (have “all-over interlock”). This means the white squares cannot be split into isolated sections cut off by black squares. A solver should be able to work their way from any part of the grid to any other part through connecting answers. It is unacceptable to have, say, the top-left corner of a crossword not connect at all to the bottom-right; such a puzzle would be rejected for having separate sub-puzzles. In short, black squares may not partition the grid into disconnected regions.
Constructors usually avoid placing blacks in the very outermost cells of the grid unnecessarily, especially in corners, as a matter of aesthetics and solving experience. For example, a puzzle with the top-left cell black would be unusual. Editors prefer a neat pattern with a balanced distribution of black squares, consistent with symmetry and not overly clustered. While not a hard “rule,”grid aestheticsare taken seriously – a well-designed puzzle has a visually pleasing pattern of blocks (which is one reason symmetry is upheld). Excessive blocks can make a grid look unappealing or too fragmented.
Word and Clue Repetition Rules
A fundamental rule across all major crosswords is that no answer may be repeated in the grid. Each entry must be unique. For example, if “APPLE” appears as an answer, you cannot have “APPLE” or even “APPLES” appear elsewhere as a separate entry. Even shorter words are generally not repeated; you won’t find two clues both answering “ERA” or “AND” in the same puzzle. The LA Times and NYT guidelines both forbid duplicate entries. This extends to derivative forms – a puzzle wouldn’t have “SING” in one spot and “SANG” in another, as those are forms of the same word (editors typically consider that a repetition of a root word). The only time a duplication might be allowed is if it is part of a deliberate theme gimmick (and even then, top editors tend to avoid identical repeats and look for more clever theme devices).
Additionally, an answer word should never appear in its own clue, nor should a major word in one clue appear as an answer elsewhere in the same puzzle. For instance, you wouldn’t see a clue like “Fruit that can be red or green” for the answer APPLE if “apple” or a form of it is also used in another clue or answer. This rule prevents giving away answers and maintains a level of challenge and fairness. If an answer is part of a common phrase or title that appears in a clue for a different answer, editors will usually rephrase one of them to avoid the overlap. Essentially, no significant word is repeated between clues and answers in the same puzzle.
For themed puzzles, constructors also avoid repeating the thematic word or gimmick outside the theme entries. For example, if the theme of a puzzle is phrases containing the word “STAR”, all theme entries might have “STAR” in them – that’s fine as an intentional theme element. But you wouldn’t also hide “STAR” in some unrelated part of the grid, nor would you use “star” in a clue in a way that reveals the theme prematurely. Consistency and tidiness are key. Outside of theme elements, any stray duplication is considered an editing flaw.
