A Doublet puzzle consists of a list of words, all of the same length. The first and last words in the list are given, and are called Anchor Words. Each of the intervening words is defined by a clue, just as in a crossword puzzle, but in addition it is formed from the previous word in the list by the application of one of a set of Doublet Rules. Currently, there are three rules, giving rise to a family of three types of Doublet puzzles.

The following graphics show a Doublet puzzle in the Crossword Express Build screen and a PNG graphic file produced by the program's print function, showing the complete puzzle. See also a  full size version of a PDF file  showing the complete puzzle.

The key features of the Crossword Express Doublet Construction function are as follows:-
  • Fully automatic construction of puzzles using anchor words ranging in number from 2 to 5.

  • Puzzles can be printed in an unprecedented range of user controlled colors and formats. Output can be sent direct to the printer or, if you install the appropriate software, it can be sent to a PDF file. The recommended software for this purpose is  Primo PDF which you can download free from their website,  although you might consider sending them a small donation if you find their program useful. Mac users will be able to create a PDF file directly from the screen provided by the printer driver.

  • A fully interactive Solve function is available to allow you to solve the puzzles "on screen" without needing to print them.