Scrabbler is a version of the game Scrabble in which players compete against the computer, each taking turns to make words on the board using randomly allotted letters.


Players add words to the board by typing them into an entrybox and then clicking on the board to indicate their start position. The program will only allow words that are in the official SCRABBLE dictionary and it will indicate errors in words or board position by changing the colour of the entrybox. After each turn the player clicks on the clockface which stops their clock from counting down and triggers the machine into taking its turn.

Players can use their turn to swap letters from their current rack or they can ask the computer to provide a hint in the form of a high scoring word.

Games can be saved so that they can be continued at a later time.

SCRABBLE® is a registered trademark. All intellectual property rights in and to the game are owned in the U.S.A and Canada by Hasbro Inc., and throughout the rest of the world by J.W. Spear < Sons Limited of Maidenhead, Berkshire, England, a subsidiary of Mattel Inc. Mattel and Spear are not affiliated with Hasbro.

Scrabbler Example

Scrabbler Example

A screenshot from scrabbler. At the top of the display is a set of buttons, a clock and the player's and machine's current scores. Below this is a white entrybox for entering words, and the player's current rack of tiles is to its right. Underneath these is the board displaying the laid tiles, those of the player in yellow and of the computer in red. The last word played is always shown in white but will be given the appropriate colour when a new word is added to the board. Each letter has a value and these are summed to give a score for each turn. When tiles are placed on squares that are not green the word score is increased. The notional sack of tiles also contains 2 blank tiles which can be used to represent any letter. When placed on the board the letter designated to these tiles is shown in lower case (for example see the "e" in the bottom row of the board).


The easiest way to get a feel for playing the game is to watch the worked example video shown below. The jigsaw icon at the top left of the window contains a menu which allows games to be saved and loaded, allows the maximum time to be changed, allows all the colours used for the board and tiles to be changed, and for the difficulty level to be set.

The difficulty level is termed the programs IQ, and ranges from 10 to 100. Winning against IQ 100 is very hard. When operating with IQ 100 the algorithm will simply choose the highest scoring word of all the words currently possible. For most players this is more than sufficient for the machine to win, but experts will succeed by using more advanced strategies. Setting the IQ to 10 means that the machine will choose a word which scores in the bottom 10% of all currently possible words. And so on. In the example the player has "won" easily because she has used the hint option for every turn and the machine's IQ was set to 10.

The word fitting code is based on the algorithm described by Appel, Andrew; Jacobsen, Guy (1988), "The World's Fastest Scrabble Program" (PDF), Communications of the ACM.

The Toolbar buttons next to the menu start a new game (dots), request a hint (wand), request the computer take over your moves (sad smiley), request letter swapping (pair of arrows), and stop the players clock (clockface).

Start a new game by left-clicking on the dots icon. The program randomly decides who gets first turn. If the clock is ticking, it is you. Type your word in the Entrybox to the left of the letter rack. When you hit Enter the program will check the word. If the Entrybox turns double word score colour the word is unacceptable. You can edit it or enter another. If the Entrybox is white the word is accepted. Even if you are only adding a single letter to an existing word you must enter the complete word. Note that the first word placed on the board must cross the central square and all subsequent words must cross or touch at least one previously laid word.

Now you have to tell the program where to put the word. This is done by clicking the board square which is at the start of the word. A left-click means the word should be placed across the board, a right-click means it should go down the board. If the position and direction are accepted the letters will be drawn on the board. If the Entrybox turns double letter score colour you've got the position or direction wrong. Note, you must enter the word before defining its position on the board and once a word is accepted it cannot be changed. Once the word has appeared on the board punch the clockface in the Toolbar. This will stop your clock and update your score. The program will then take its turn and restart your clock.

If you are unable to go or are unhappy with your current letters you can replace any number of them (while there are still at least 7 in the notional sack) by clicking on the swap icon and then typing the letters you want to discard into the Entrybox. Again finish with Enter. If the Entrybox turns triple word score colour the letters contain an error. Otherwise the letters will be replaced. Punch the clockface.

When it is your turn and a move exists you can request a hint by clicking on the wand in the Toolbar. A word will appear in the Entrybox. If you can work out its location, click the board at its start position. Otherwise, a click on the wand will put the word on the board. Punch the clockface. Note that the program will always use IQ 100 for hints.

When the clock flashes and the clockface icon is greyed out the game is over and the scores shown are the final values.

Scrabbler Worked Example

A video from scrabbler. The player starts the game and is allotted her letters. She sees the clock is ticking so it is her turn to go. She enters "PINE" into the white box, types "Enter" and the colour stays white so she knows it is an acceptable word. She positions the cursor above the central square and right clicks. The words is placed and she quickly stops her clock by clicking on the clock icon. The program instantly places a word from the official scrabble dictionary (which only experts will recognise!), and it is the players turn again. She enter "LION". A bit later she decides she does not like her current letters and so for her turn clicks on the arrows denoting swap and enter "IIU". The program swaps them and she clicks the clock icon. After a few more turns she clicks on the sad smiley, signalling the program to take over her moves in addition to its own. It instantly finishes the game and displays the finished board.


As marked on the tiles, each letter has a score. The score for a turn is the sum of the scores for all new words created by the placed tiles, and is increased by double and triple letter squares, and double and triple word scores. You also get a bonus of 50 if you manage to use all your tiles in a single turn. The sack contains two blank tiles which are wild cards that can take any letter value when played and retain that letter throughout the game. They score 0. Blank tiles, once added to the board are given the letter they represent, but written in lowercase.

The game ends when the tiles run out or you and the computer have been unable to place a tile for 6 consecutive turns. The clock will flash, the clockface icon will be greyed out and the scores shown will be the final totals.


The "Set Colour" option in the puzzle menu enables the following colours to be changed: player's tiles, machine's tiles, tile text, single letter squares, double letter squares, triple letter squares, double word squares, triple word squares. Along with all the other settings these can be saved using "Save Settings" so that they will be loaded next time the program is started. An example of a different set of colours in shown in the adjacent Figure.

scrabbler colour example

scrabbler colour example

The colours used can be changed by the player.


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. If you are not familiar with the game you may find some of the words allowed rather surprising as can be seen from some of the weird and wonderful words shown in the Figures. But they are all from the official list...

When SCRABBLE is played with a board and tiles there can be doubts about the acceptability of the words made by players and they can be challenged by their opponents, after which the words are checked in a dictionary. If the words are found to be incorrect they are removed from the board and the player forfeits that turn. In pzl scrabbler there are no challenges: the game contains the dictionary and always knows all the possible words and where they can fit on the board. Therefore, the program will only accept words from its dictionary that will fit on the current board and so the opportunities for challenges do not arise.

Saving and Loading Games

The puzzle menu contains options for saving and loading games. A typical saved game is shown here. Please note the following. When a saved game is loaded the clock will start counting down from its current maximum time and the tiles already laid will all be given the colour used by the player. All subsequently laid tiles will be given the current player and machine tile colours. At the start of a loaded game the sack will contain only the tiles that remained when the game was saved. There is currently no error checking when the game is loaded so please do not edit the files containg saved games!