[First, three links:

• The current puzzle • Our puzzle-solving guidelines
• A Nation puzzle solver’s blog]

The other day we found ourselves in conversation with our old friend Fraser Simpson, the puzzler who sets the weekly Saturday cryptic in the Globe and Mail. In the midst of shop talk about principles of clueing and grid design, Fraser let loose with an offhand observation: “I do notice,” he said, “that you guys put a lot of three-letter entries in your grids.”

There wasn’t any malice behind it, but the accusation stung a bit. No one likes to see three-letter words in a cryptic crossword grid (regular crossword grids are a different story), and we’re no different. The reasons are multifold. For one thing, in a checkerboard grid every other letter in an entry is checked by the crossing word (see here for more on this topic). That’s fine in a longer word, but a three-letter word with the first and last letters filled in is almost pre-solved.

More importantly, it’s practically impossible to write an interesting clue for a three-letter word—there’s just not enough to work with. You can’t assemble a good charade or container clue, and anagrams and even reversals provide minimal variation.

Still, there’s a difference between forbidding something absolutely and trying to avoid it as much as possible—which has been our approach to three-letter entries. The most common reason to put them in a grid has been the constraints imposed by a group of (usually long) theme entries. And when we do have three-letter entries, we almost always clue them as part of a phrase with other entries, which alleviates the problem of finding interesting wordplay.

So the notion that we were lax about these matters seemed unfounded, and we sputtered an indignant protest: “We hardly ever use them, and every time we do there’s been a good reason!”

The truth, it turns out, lies somewhere in between. A check of our puzzles over the past year reveals that three-letter entries have appeared in ten puzzles, which is far more than we’d thought. But in every one of those cases, the three-letter entries were forced by a tough-to-fill thematic grid (e.g., #3207, #3224, or #3230), or used as part of a longer, multi-word entry (most notably in #3222, with its three-letter orgy TEA FOR TWO AND TWO FOR TEA), or both. And in some cases—as with ONO in the Beatles-themed #3210 or OIL and GAS in the Arab League-themed #3201—the three-letter entries were themselves thematic. This was never something we did lightly or inadvertently.

In other words, our approach to three-letter words is in keeping with our attitude to nearly every aspect of crossword construction: conscientious but not doctrinaire. If three-letter words help make a theme possible or lead to a clever clue, then let a few of them bloom!

What are your thoughts about three-letter words? Please share them below, along with comments, questions, kudos or complaints about the current puzzle or any previous puzzle.