Most of the crossword puzzle modules have the option to determine the level of difficulty. In these cases there are always 8 lexical levels of difficulty, although the dialogue for the main dictionary allows 9 levels.

The reason for this is that, for example, CrossWordGenius selects words within the range of 1 - 7 when 3 is the level of difficulty in the blueprint, and not only words from the 3rd level. To use words of a single lexical difficulty level would mean that there are fewer words with too many boring repetitions.

The graph shows which levels CrossWordGenius uses. The levels of difficulty on the x-axis (from left to right) are the levels of the blueprint. The levels on the y-axis (from bottom to top) are the levels saved for each word in the main dictionary.

The words CWG selects depend on three factors:

1  Which Words are Actually Possible (Length, etc.)

2  The Difficulty Level of the Blueprint

CWG uses the following logic to choose the words: The blueprint level 5 uses all words, i.e. the levels 1 - 9 of the dictionary. The blueprint level 4 uses 1 - 8, blueprint level 3 uses 1 - 7, blueprint level 2 uses 1 - 6 and the lowest level of difficulty 1 uses only 1 - 5. The other direction for more difficult puzzles looks similar: blueprint level 6 uses 2 - 9, blueprint level 7 uses 3 - 9 and the highest level of difficulty 8 uses 4 - 9.
 
The difficulty Level of the blueprint is always absolute, i.e. 3 means that selected words are always within the range from 1 - 7 and never 8 or 9.

3  The Average Level of Difficulty of already selected words

CrossWordGenius uses words within a range of levels. To ensure that a blueprint level of 3 (range 1 - 7) does not choose only words with the level of 7, CWG always calculates the new average level of difficulty of already selected words. If the calculated average level tends to be too high CrossWordGenius automatically uses easier words in order to decrease the average level. A similar adjustment is made if the average level is too low.
 
When the puzzle compilation is ready, an additional check of every level of difficulty takes place during a final Validation.