In the real world Boggle is traditionally played with lettered dice, pen and paper. The aim of the games being to find as many different words as possible in a randomly generated grid of letters. Here the program generates and displays the grid and players enter as many of the hidden words as they can find.
Words are entered by left clicking on the letters in turn, or by typing on the keyboard. Letters may be used any number of times, but only once per word. The sequence of letters in a word must be from touching squares. Unless it is at the edge of the grid each square touches eight others: left, right, up, down and four diagonals. As the letters are entered they appear in the entry box just under the grid. When words are completed and the program has checked that they are in it's dictionary they are moved to the scrolling list directly below.
At the top of the display is a Toolbar. The jigsaw piece button at the left is a menu. To the right of the puzzle icon is the boggle icon used to start a new game, and a sad smiley used to show the solution. Right again is a clock which ticks every 5 seconds. Using the Menu the player can select the type of game to play (against the clock, or find all); whether or not the squares should be shaded to indicate the numbers of words that originate from them; the input mode (mouse or keyboard); the time limit for a game against the clock; the minimum word length (3,4,5 or 6); the grid size (4,5 or 6 squares a side); whether or not to allow cross-over words. All these values can be saved using "Save settings" so that when the game is restarted they will be set automatically.
Boggle Worked Example
The player starts a game in which the cells are not shaded. She starts entering words using the mouse (left click to select a letter, right click to end a word and middle click to delete a letter). As the words are entered the counter to the right of the sad smiley increases accordingly. After only 5 words she gives up and uses the sad smiley icon to show the solution which shows she got 1.3% of 380 possible words. Next she uses the menu to request that the cells are shaded to show how many words originate from them (their colour will fade to white by the time all the words which start from them are entered). She then clicks the game icon and looks at the generated puzzles, rejecting two of them and then settling on the third. She has a few spelling problems and then gets the solution to end the game.
Letters may be used any number of times, but only once per word. The sequence of letters in a word must be from touching grid elements (squares). Unless it is at the edge of the grid each square touches eight other squares: left, right, up, down and four diagonals.
If the cross over option is used, finding all the words is much more difficult. In this mode additional words can be made by exiting the outer edges of the grid to enter squares on the opposite side. Please see the adjacent figures for an example.
Cross over mode showing the path of the word "COLT" with dots: black at the cell exit points, green at entry points.
N GTN G --- R|OLR|O C|HFC|H N|GTN|G --- R OLR O
The program uses a built-in dictionary representing the Collins Scrabble Word List 2012, which contains 270,163 words. It was downloaded from the zyzzyva site. Within the program the dictionary is represented as Directed Acyclic Graph.