The word search dialog is separated in two sections. Left you can check whether or nor the dictionary contains a word, and right you may search for words with several options. Depending on the word check mode the right or as well the left section is disabled during the game to avoid cheating.
Enter the word you are looking for at the input at word. The background is highlighted in red if the dictionary doesn't contain the word, and yellow in case of a known word whose category is disabled. The background remains white if the word is found, and id, category, and meaning are shown at number, category, and meaning respectively. You may also browse through the dictionary by changing the number (aka id).
If you select another category from the dropdown menu it becomes effective immediately. For example, if you enter SNAFU (which is part of the TWL word list), and select SWOPODS from the category menu, the background of the word is colored yellow, if you have SWOPODS deselected. And you can change the meaning, e.g. 'to cause confusion' into 'SNAFU is just an abbreviation'. Just click add/change to apply your input to the dictionary. Finally it is also possible to enter a new word, like 'ABC'. After (optional) assigning to a category and providing a meaning it can be added to the list with the 'add/change' button. And last but not least words are removed from the list with delete.
If you made changes to the dictionary the program asks on closing if the updated list should be saved.
The right section provides four different ways to find words: wildcards, regular expression, variation, and anagram. The search is applied to the pattern. You can enter only those letters that are part of your current letter set, e.g. with the English set you cannot enter umlauts ÄÖÜ.
The header of the list shows how many words have been found. Click this header to sort either by word length (most letters first) or by the lexical order (A..Z, special characters). If you select an entry it is shown on the left side of the dialog with its category and meaning. And as a convenience function it is possible to copy the whole list using the dropdown menu or per ctrl+C.
A wildcard character can be used to substitute one character or all characters in a string. With a search pattern
*X all words are found ending with X, with
Y* all words that start with Y. And
Y*X retrieves all words that start with Y and end with X. If you want to substitute only one letter you can use a question mark:
Y?X will find all three letter words starting with Y and ending with X.
The wildcard search is just a subset to regular expressions. It is much more powerful but with the trade-off of rather complex queries. There are a lot of tutorials available on the Internet (one in the Scrabble3D forums but in German only).
The search works in terms of enumerative combinatorics. The pattern ABC generates A,B,C,AB,AC,BA,BC,CA,CB,ABC,ACB,BAC,BCA,CAB,CBA and compares this list with the dictionary. One or more joker can be added with a question mark. In contrast to the two previous options no word from deactivated categories will be retrieved.
The search for anagrams is executed similar to the Scrabble-like variation but filters the resulting list so that only words with the same length as the pattern are reported.