A codeword is a completed crossword but with the letters represented by numbers. The object of the game is to work out which number corresponds to which letter and hence to reveal the finished crossword. It's a challenging pattern recognition game and test of word power (and sometimes, spelling).
At the start of each game the program randomly chooses a crossword from its collection of 3000 puzzles and then randomly assigns the numbers 1-26 to the letters A-Z. The numbers assigned to each letter are displayed at the top left of each square in the crossword. By default, three of the letters are also exposed as clues to help get players started. Their task is to work out all the other assignments and hence solve the puzzle. The two top rows of the board list the numbers from 1 to 26, and the row below the letters A to Z. By responding to the mouse these three rows provide interaction with the program. As can be seen in the video example, as the mouse cursor passes over squares in the top two rows it lights up in green the corresponding squares in the crossword grid. This is very much more convenient that hunting around the grid to find the numbers. The crossword grid itself is not an input device and will not respond to the mouse. To assign a letter to a number players left click on the letter in the letters row, then left click on the number in the numbers row (this also works in the reverse order). If players think they've made mistakes they can undo assignments by right clicking on the letter in either row. At the very top of the display is a Toolbar. The jigsaw piece button at the left is a menu which allows players to set the number of initial clues. Next to the menu is an icon which is used for selecting a random puzzle from the program's 3000 built-in puzzles; a wand to request an extra clue; a thumb to check and correct errors, and a sad smiley to show the solution. The puzzle number and a clock are displayed to their right. To select a particular puzzle the player can enter its number into the puzzle number box and hit Enter. If the number is accepted (0-2999) the corresponding puzzle will be loaded.
Codeword Worked Example
The player starts a game and moves the cursor around in the number rows causing the corresponding cells in the codeword to light up. Eventually she thinks she spots a pattern which could correspond to the letter "E" and so she clicks on the number row and the letter row to set the number to "E". Next she decides which number corresponds to "I" and guesses that one of the words is "PICTURE". Having set the number for "T" she realises this is probably wrong and undoes it by right-clicking on the "T". Then she thinks she recognises a patter of "A"s and guesses that "PICTURE" is instead "PICKAXE" and proceeds accordingly. Finally she clicks the sad smiley icon to request the solution and so end the game.
Clicking on the wand simply adds the next rarest letter to the grid.
Checking for Errors
Clicking on the hand button causes the program to check the puzzle for errors. If errors are detected the hand will flip to the thumbs down position and the incorrectly assigned letters will be highlighted in yellow. A further click on the hand will correct the errors.