Cryptic crosswords, like all puzzles, are meant to be solved. Thus, while they may be challenging, they also need to be fair. Unfortunately, it is not at all clear where to draw the line between fair and foul.

One example of a practice that almost all concerned would agree is unfair is the indirect anagram, where the solver is supposed to anagram a synonym of a word in the clue. Still, our predecessor, Frank Lewis, would use indirect anagrams on occasion, and the clues could always be solved, because he only did this with very short word fragments, and gave transparent definitions for the words to be anagrammed. We do not use indirect anagrams, but we agree with British constructors who routinely use abbreviations as part of anagram fodder. Once you know to expect this, and as long as the abbreviation is standard, we think this spices things up a bit, while still remaining fair. Here is one example:    ALTER Change in real time! (5)

Also like the Brits, we occasionally separate anagram fodder into chunks, as in this example:    TROPICAL Hot car and pilot in smash-up (8)

This practice would be unfair in a venue where solvers expect all anagram fodder to be one continuous string. But once you know we might do this, you know to be on the lookout for it. Likewise, once solvers know that once in a while we mess with spacing in our clues, they get used to watching for that.

Here are some of our thoughts about what makes a fair Nation puzzle.

Some of it is about the way the entries cross each other:

• At least half the letters in each entry should be checked, except on rare occasions in the case of very long entries, where the ratio can drop slightly below half.

• There should not be consecutive unchecked letters.

• If an entry is obscure or its clue very difficult, the checked letters should be helpful. (For example, if the entry is DACE, it is the consonants that should be checked.)

• An entry which requires specialized knowledge (e.g. sports) should not cross another one with the same requirement, as that would make the crossing useless to those not familiar with this domain.

Some of it is about the relationship between an entry and its clue:

• An entry that would be obscure to many solvers needs a straightforward clue.

• A definition need not be very specific, as that could make the wordplay superfluous. But if it is very vague, the wordplay needs to be accessible.

Some of it is at the macro level of the whole puzzle:

• If a puzzle has some obscure entries and/or some difficult or unorthodox clues, this should be balanced with some easy or straightforward clues, typically anagrams and hidden words.

A general principle is that if some information is taken away from the solver, something must be given back. Often it just works that way. For example, clues that reference other clues offer less information to the solver. But some information is regained by going back and forth between those clues, and solving one helps solve the other. This even works in the case of two clues that reference each other. If, for example, the entries are anagrams of each other, getting some letters for one of them provides information about the other.

In the end, there are no hard and fast rules for fairness. We strive to be reasonably consistent, so that solvers know what to expect from us. We know that the level of difficulty of our puzzles varies from week to week, but we hope that we are never unfair.

Cluing challenge for this week: COUNTY FAIR. To comment (and see other readers’ comments), please click on this post’s title and scroll to the bottom of the resulting screen. And now, four links:

• The current puzzle

• Our puzzle-solving guidelines | PDF

• Our e-books (solve past puzzles on your iOS device—many hints provided by the software!)

• A Nation puzzle solver’s blog where every one of our clues is explained in detail. This is also where you can post quibbles, questions, kudos or complaints about the current puzzle, as well as ask for hints.