Sample Encodings
Over time, some encoding schemes have been used so frequently that they've formed a kind of basic vocabulary for Puzzle Hunters. Here are some things to look out for as you try to determine how to extract a final answer.
Number to Letter Conversion
Numbers between 1 and 26 often represent indices into the alphabet, where
1=A, 2=B, and so on through 26=Z. If a puzzle solved to the following list
of values: 3, 15, 18, 18, 5, 3, 20, you would translate that into the final
answer CORRECT. If numbers are outside this range, sometimes you need to
bring them into that range via a mod 26 operation: divide the number by 26
and use the remainder, treating 0 as 26.
ASCII to Letter Conversion
Numbers in the 65-90 range often represent the ASCII code values for the
alphabet, where 65=A and 90=Z. 97-122 can represent lower-case ASCII codes.
Indexing
Another extremely common use of numbers in puzzles is as an index into other
text. A clue with a number 5 next to it might mean that after solving the
clue, the important thing is the fifth letter of the answer. Typically, a
puzzle using indexing will require you to index multiple times, often using
a different answer and number each time, to extract a series of letters
which can then be read as something meaningful.
Implied Indexing
If the puzzle resolves to a list of answers and there is no numeric data to
suggest indexing, the answer may be an acrostic, which is essentially an
implied index of 1 for each answer. Try reading only the first letters of
the answers. Another common implied index is the "diagonal read"-an index
of 1 for the first answer, 2 for the second, 3 for the third, and so forth.
Binary
A stream of data with only two different values-black and white, true and
false, dead or alive, 1 or 0-often represents binary values. The most
useful binary values are 5-bits long, since that's the smallest number of
bits required to represent the numbers 1-26 (which can in turn be converted
into the letters A-Z).
Morse Code
The other choice for a stream of binary data is Morse code. Data with three
different values can also be Morse, with the third value used for letter
breaks. A puzzle might be encode Morse more visually, by containing dots
and dashes in the puzzle (for example, as the stripes or emblems on national
flags).
Semaphore
Semaphore is a flag signaling system in which the alphabet is represented by
holding two flags at various angles from the body. In puzzles, if a data
stream consists of compass directions, angles, or lines emanating from a
common center, it might be semaphore.
Braille
Braille is a system of raised dots used to allow non-sighted people to read
by touch. Each letter in the Braille alphabet is composed of a 2x3 grid of
dots, some of which are "on" and some "off". Any time your data can be
subdivided evenly into a 2x3 grid, consider trying to treat it as Braille.
Nautical Signal Flags
The system of international maritime signal flags is a way of representing
every number and every letter of the alphabet in signals to or from ships.
Each flag features a simple pattern in a palette of five colors: red, white,
blue, black, and yellow.
NATO Phonetic Alphabet
The NATO alphabet assigns code words to letters of the alphabet (ALPHA,
BRAVO, CHARLIE, etc) so that critical combinations of letters can be
pronounced and understood via radio or telephone.