Nouns are the objects in a logic puzzle, and are usually the easiest pieces of information to uncover. What may be harder is how to categorize the nouns. For the logic puzzle "Five Houses", here are the nouns for this puzzle, where the noun types are: House, Color, Nationality, Hobby, Pet, and Drink. Note that the names of the noun types are singular, not plural. For this puzzle, there are five nouns for each type. The following statement is true for all logic puzzles.
For every logic puzzle, you must have the same number of nouns for each noun type.
The nouns are used in virtually every aspect of a logic puzzle. They are used in defining the links in a logic puzzle. They are used in building facts, and in programming rules. While the logic puzzle is being solved, the marks tell us if two nouns are or are not with each other. The Chart displays the pairings between any two nouns.
The only thing that is not affected by the nouns are the verbs.
Here are the links for our example logic puzzle. The links are named "with", "directly to the right of", and "next to". All of the links use the noun type House. You can visually see how the links are defined.
Usually, the order of the nouns within a noun type is not important, but there is one major exception:
If a noun type is used in defining a link, then the nouns for that type must be in a logical order.
While most logic puzzles will give you all of the nouns in the puzzle, some very difficult puzzles may not give you all of the values of the nouns. This means the values must be calculated by one or more rules.
Nouns where the initial value is unknown are called placeholders.
Usually these values are numeric, such as the number of people who attended a talk in "Astrophysics Conference", or the age of a salesperson in "Dandy Salespeople".
Determining the nouns, and organizing them by type, is one of the first tasks you must perform for any logic puzzle.