From the NannyMUD documentation

LAST CHANGE

2005-10-27 by Gabe

FUNCTION

NAME
        set_puzzle - Remember that the player solved a given puzzle.


LOCATION
        In /obj/player.c through /obj/puzzle.c.

AVAILABILITY
        This function can be called by any object.

SYNTAX
        int set_puzzle(string puzzle_name)

DESCRIPTION
        This function stores the information that a given puzzle has been
        solved by the player object it is called in.


RETURN VALUES
        True if the puzzle was not already set.


NOTE
        Do not call query_puzzle to determine if you should call set_puzzle.
        Instead use the return value from set_puzzle to determine if you
        should reward the player.


NOTE
        A good puzzle name always starts with your full name, followed by an
        underscore, followed by a short word, normally a noun. Verbs and
        adjectives will generally only make the string unnecessarily long.
        Puzzle names should be short, unique and to the point. There
        is no need to capitalize any part of its name.


EXAMPLE
        if (player -> set_puzzle("gabe_thing")) {
          player -> add_exp(2000);
        }


SEE ALSO
        query_puzzle in lfun/player/query_puzzle