One consults the I Ching by generating the lines of a hexagram while holding a question in mind. Two traditional methods involve manipulating a bundle of 50 yarrow stalks or tossing three coins to generate a number in the range 6-9 for each of the six lines of the hexagram. The individual numbers designate:
The lines are generated and ordered from bottom to top; the bottom line is "the beginning" or "in the first place", the line above it is "in the second place", and so on up to the line "at the top" or "in the sixth place".
The hexagrams are numbered in a traditional ordering that is somewhat obscure, although it pairs hexagrams whose lines are opposites or reversed in order. A hexagram is composed of two trigrams which are associated with particular attributes and natural phenomena. The text has a judgement giving the overall meaning of the hexagram, an image often metaphorically related to the component trigrams, and a section for each changing line. A line marked with a circle is considered a "governing ruler" of good character. A line marked with a square is the "constituting ruler" that gives the hexagram its characteristic meaning, but is not necessarily of good character. If any lines are changing, then the hexagram resulting from the changes is also presented. Since there are six lines each with four possible states, there are 4096 possible readings that can be generated.
The coin method of casting a hexagram is simulated. The question typed in (if any) is used to influence the output of a random number generator along with other current circumstances.
The base URL http://hexadecimal.uoregon.edu/cgi-bin/ching will produce a random I Ching reading. Appending a question mark and six digits each in the range 6-9 will give the reading for that specific casting. Example: http://hexadecimal.uoregon.edu/cgi-bin/ching?899876.