[First, three links:
• The current puzzle 
• Our puzzle-solving guidelines 
• A Nation-puzzle solver’s blog  where you can ask for and offer hints, and where every one of our clues is explained in great detail.]
In a previous post  we quoted the late French writer Georges Perec on puzzles in general. Perec was also a crossword constructor (in French, naturally), and he wrote an interesting essay about that. (See “Thoughts on the Art and Technique of Crossing Words,” by Georges Perec. An annotated translation , by Henri Picciotto and Arthur Schulman in The Believer, September 2006.)
That essay’s introductory paragraphs are perhaps the best summary of the task that faces us every week when we create puzzles for The Nation:
The construction of a crossword consists of two operations that are quite different, and in the end perfectly independent of each other. The first is the filling of the diagram; the second is the search for definitions.
The filling of the diagram is a tedious, meticulous, maniacal task, a sort of letter-based arithmetic where all that matters is that words have this or that length, and that their juxtapositions reveal groupings that are compatible with the perpendicular construction of other words; it is a system of primary constraints where the letter is omnipresent, but where language is absent. Contrariwise, the search for definitions is fluid, intangible work, a stroll in the land of words, intended to uncover, in the imprecise neighborhood that constitutes the definition of a word, the fragile and unique location where it will be simultaneously revealed and hidden. The two operations imply mental faculties that could almost seem contradictory: in the first, one proceeds by trial and error, starting over twenty or thirty times a grid that one always deems less than perfect; in the second, one favors intuition, fortuitous finds, sudden illumination; the first is done at one’s table, with obstinacy and tenacity, groping, counting, erasing; the other is rather done at any hour of day or night, without thinking about it, strolling, letting one’s attention float freely in the wake of the thousand and one associations evoked by this or that word.
As it turns out, the introduction of the computer has not changed this state of affairs. We use software and word lists to help us fill the diagram (more on this in a future post), but that does not change the obsessive nature of that phase. Moreover, it provides very little help in the wandering that is required for the writing of the clues.
Here is Perec on definitions:
For the definition to start to function, there must be ambiguity. The simplest method, in a sense the second degree of the definition, consists in representing the word to be found (the signified) by a signifier that usually represents something else.
What, in the end, characterizes a good crossword definition, is that its solution is obvious, as obvious as the problem had seemed insoluble as long as it was not solved. Once the solution is found, one realizes that it was very precisely stated in the very text of the definition, but one did not know how to see it, the whole problem being to see in an other way.
The same applies to cryptic clues. Of course, puzzles exist at various levels of difficulty, and it does sometimes happen that one cannot figure out how a given clue works, even knowing the answer. But we are one step ahead of Perec and his contemporaries: We have the Internet! See the link at the top of this article to see full explanations of any clue of ours that you don’t understand.
What makes a good clue? Share your thoughts, as well as comments, questions, kudos or complaints about the current puzzle  or any previous puzzle.