Online Guide to the Engima

Preface to the Guide
History of the NPL
Membership Information
Sharing the Puzzles
      Sharing the fun
      Combining Talents
Editorial Verses
      Acrostical Enigma
      Apt. . .
      Baltimore Deletion
      Baltimore Transdeletion
      Bigram. . .
      Brookline Letter-Change
      Change of Heart
      Combination Padlock
      Diastichal Enigma
      Enigmatic Rebus
      False derivative
      Group flat
      Head-to-Tail Shift
      Heart Transplant
      Letter Bank
      Letter Change
      Letter Shift
      Order Takeout
      Overloaded. . .
      Phonetic. . .
      Phrase Shift
      Picture. . .
      Progressive. . .
      Redro takeout
      Repeated-Letter Change
      Repeated-Letter Deletion
      Reversed. . .
      Sound Change
      Sound Shift
      Telestichal Enigma
      Terminal Deletion
      Trigram. . .
      Welded. . .
      Word Deletion
      Word Substitution
      Solving the Rebus
      Browse the Flat Pages
Introduction to Forms
      From A to O
      From P to Z
      Form Modifiers
      Constructing Medium Crypts
      Solving Cryptograms
      Other Solving Approaches
      Solving Cryptics
      Composing Cryptics
Reference Books
      Non-Guide Flats
      Non-Guide Forms
      Non-Guide Extras
      Where to Find It
      Form Notation
      Italian Picture Puzzles
      Abbreviated Guide to Flats
      Mobile Guide to Flats

© Copyright 2013 by
the National Puzzlers' League

Through an alphabetical quirk, the first puzzle in our list is also among the hardest to master. If you’re reading this Guide for the first time, we recommend learning about the other flat types first, returning here when you’ve had more practice.

The solution to an acrostical enigma, or AE for short, is a word or phrase. This solution is divided into chunks of two or more letters each; each chunk is clued in a different couplet in an unusual way. The chunk plus the first two or more letters of the couplet form a word or phrase (called the part-word) that is clued somewhere within the couplet itself. A final couplet clues the entire solution.

A. Relaxing on Saturday morning I am;
I smell something burning, but who gives a damn?
B. Gargantuan flames billow smoke in the air;
Some building is blazing, but why should I care?
C. I only want something absorbing to read.
A Harlequin tearjerker: just what I need!
D. Red engines zip by with complete audibility,
Disturbing, with bells, my beloved tranquility.
  It’s getting quite warm now. What can be the matter?
Let’s turn up the fan and ignore all the clatter!

In part A, the letters AFI plus the letters RE from the beginning of the couplet form the part-word afire, which is clued by “burning.” So the first chunk of the solution is AFI.

The remaining part-words are: CI-gar (“smoke”), ON-ion (“tearjerker”), ADO-red (“beloved”). Putting all the chunks together -- AFI, CI, ON, ADO -- produces the solution: aficionado (clued by “fan” in the final couplet). (To save space, on the solutions page, this entire solution would appear simply as “AFIre, CIgar, ONion, ADOred.”)

In an AE, only the full solution is enumerated. Both the part-words and the full solution are tagged when necessary, and hyphenated words or phrases among the part-words are noted.

Misleading clues are common in acrostical enigmas. Be on guard for words that have other meanings (like “fan” in the above example) or that can be used as parts of speech other than those used in the verse. Definitions can be phrases, too. In one acrostical enigma, the solution was bodhisattva, and the definition (“future Buddha”) was concealed in this final couplet:

Each hopes to live, with verve and vim,
The future Buddha plans for him.

Punctuation may be misleading. In one acrostical enigma (with a verse about the Three Stooges), the solution was pertussis, and the definition (“whooping cough”) was deceptively hidden in this final couplet:

Curly will start “whoop-whoop-whoop”-ing,
Cough up feathers, get kicked while stooping.

The entire couplet may indicate the solution or part-word, rather than any single word or phrase, as in this couplet clueing BY-PROduct:

Ductile is my mind from drink;
Gin also shows me gnus (in pink).

The gnus here are a by-product of the gin and so refer to the part-word. This sort of clue isn’t used often; almost always the couplet has a direct definition of the part-word.

Also used are couplets that clue by example, as iambic hexameter lines clueing alexandrines, or a line with “he brung” clueing solecism. Very rarely, the entire verse is the clue. For example, an AE on eclogue (a dialogue between shepherds) was written as an eclogue and had no final couplet at all.

However misleading a definition may be, it must match the word or phrase it defines in number, tense, case, and so forth. The definition for AVERage can be “mean,” as in “A gentle smile can mean a lot,” or “Aged men, mean-spirited.” But the definition can’t be “means” or “meaning” or “meant.” If the definition is “means,” as in “A gesture means a lot,” then the part-word had better be AVERages.

At least two letters of each part-word must start the couplet; there should be three if one letter is just a plural S or a past-tense D, and four with plural ES or past-tense ED. “Edna loved a bonny lad” is poor help for a solver looking for ADORed; “Espy the animals” is an equally stingy clue for MULes.

In some AEs, a single line or a quatrain is used for each clue instead of a couplet.

In the double acrostical enigma, the same puzzle legitimately leads to two different solutions. One example (and a tough one-many of the parts are uncommon):

1. ACROSTICAL ENIGMA (3 7) (A = NI2, hyph.;
*B = not MW; C = NI3, NI2 more explicit)
2. ACROSTICAL ENIGMA (*7 5) (NI2+) (A,
C = NI3+; B = NI2 phrase)
A. Ate a six-course dinner (cardinal sin!)
Waiting for the noise here to begin.
B. Rollo croons a song the people sing;
Flynn is playing back-up to his Bing.
C. Entrance planned, and grinning like a cat,
Tina belts out western tunes with Pat.
  Troubles fade with music and a meal-
These two can distract from what is real.
=Jo the Loiterer

The first solution is red herring: RED-Hat (clued by “cardinal”), ERrol (“Flynn”), and RINGent (“grinning”). The second is Norfolk capon (another term for a red herring): NORate (“noise,” as a verb meaning to spread a rumor), FOLK CArol (“song the people sing”), and PONent (“western”).

In the reversed acrostical enigma, the solution is reversed before being broken into its chunks, so that the solver must put the pieces together and then reverse the whole thing to read the solution. For example, the solution pertussis might be broken into the chunks sis, sut, and rep, and then clued in couplets as usual (with the A couplet clueing SISter, and so on).

The phonetic acrostical enigma is rarely seen in practice. There are two separate parts of the puzzle that can be phonetic: each part-word must overlap the start of the couplet phonetically and not literally; the final solution can also be a homonym of the sequence of part-word elements. For example, the part-words CYcloid, KEYhole and NAUGHTiness might be clued by “curve,” “intimate,” and “terrible,” respectively. This would be phonetic if the first words of each part-verse were “cloyed,” “wholesome,” and “Enos.” The part-word elements then combine, also phonetically, to give Psyche knot (a hairstyle). The example below is likewise phonetic in both respects.

A. Really banal jokes he likes to blab
To captive hearers-riders in his cab.
B. Aloud I laugh a faint “ha-ha” but think,
This guy’s a jerk-a silly, worthless gink.
C. Geysers spout, and so does he; I view
“Halloo” from him as cause to cringe, and do.
D. Scenario: this plaudit-greedy hack
For all his rotten jokes will get the sack.
  A tremor (Richter seven) shook us good;
He joked, “Well, folks, there goes the neighborhood!”

The solution: A = GHArry (clued by “cab”); B = LOSel (clued by “worthless gink”); C = HEU gase (clued by “view halloo”); D = MERcenary (clued by “greedy”); giving gallows humor.

See also: diastichal enigma, telestichal enigma


A telestichal enigma is like an acrostical enigma, except that the part-words overlap the ends of the lines (by at least two letters), not the starts.

Y. I don’t know the name of this “flower from Gaza”;
It goes in this square (it’s a form, not a plaza).
Z. Forgive the transition: I’ve nothing but boos
For the strange obscure words that the formist must use.
  When I don’t know the words, and I don’t have a clue,
What National Puzzlers’ form can I do?

The solution: Part-words: azaLEA, seGUE; Answer: LEAGUE (“what National Puzzlers form”).

The telestichal enigma was reintroduced to the NPL by Dart with information on past use from Trash.


The diastichal enigma (DE) is a variant of the acrostical enigma. Each part-word in a DE is clued by a couplet, and the answer word overlaps the break between the couplet’s two lines, using at least one letter from one line and two from the other. As in an AE, the pieces from the part-words not taken from the verse are strung together to form the answer:

A. My love life’s in pieces! I just can’t decide:
Stay with my boyfriend or let it all slide?
B. He acts like a sleazy and cheap gigolo.
Right now, he can stay, but soon he may go!
  He thinks our relationship’s only a game.
I feel our connection’s still there all the same.

The solution: part-words: deBRIs (“pieces”), loDGEr (“he can stay”); Answer: BRIDGE (“game,” “connection”).

The diastichal enigma was invented by Beo and first appeared in December 2001.