The chosen board determindes the dimension of the game. The classic Scrabble game is played on a 2D board with 15x15 squares, Superscrabble on 21x21 squares, and 3D games have a further dimension. Additionally, the board types may contain of different bonus squares like the 4 times of word- or letter value in case of Superscrabble.
Changes to the board become effective with start of a new game.
In this dialog you can choose one out of the four predefined configurations. The preview serves as an indicator how the board will look like. Colors depend on the actual settings for board colors.
Scrabble3D offers as well the opportunity to create your own board that can contain fields which are counted as malus. To design such a board you have to switch to the configuration (available only in the extended mode). Self-defined boards will be listed under the name 'special'.