It is a combination of 2of12inf + 3of6game. I chose these because they have inflections (all forms of the word, for example: cheese, cheeses, cheesier, cheesiest, cheesiness, cheesy) and because they already filtered out words not acceptable in most word games -- like acronyms/initialism (FBI, USA), hyphenated words (tractor-trailer), phrases, and proper nouns. Generally, these categories aren't allowed in other games like Scrabble, either.
This means you shouldn't find cities, days of the week, months of the year, zodiac signs, etc. in any of the lists. This is true for 12dicts, but the Scrabble dictionaries are very inconsistent. For example, British Scrabble
does not contain Aquarius, Christmas, February, London, but
does contain Gemini, Easter, November, Berlin.
