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Knowledge: Decipher Script 2-Applications

By Michael 'Old Man' Ullom

Welcome back! Last time we covered the basics of Decipher Script and were left with a question: How will help me? We're going to answer that now. We'll cover setting DCs, Ciphering In-Game Documents, simple examples of military encrypting inventions, and puzzles for use in play.

Setting The DC

There are one or two checks when deciphering a script. Decipher script: one to put symbols into plain English, and possibly another roll to understand the meaning (i.e., an assassination attempt described as a treatise on alchemy might require an alchemy check) . In either case, this is an opposed skill check-The codemaker vs the codebreaker's. Decipher Script is used for making ciphers-the knowledge required to make a good cipher and break it are similar.

The Simple Version

A successful opposed Deciphered Script check vs. the codemaker's roll will put the document into English letters with an optional one to understand the meaning. The ciphered document is understood without a check by someone who has the key.

Advantages. On par with the rules, easy for use in play. Summarizes the struggle in one roll.

Disadvantages. it is difficult to use excitingly for spy or information-based campaigns, and doesn't reflect the painstaking work that goes into breaking ciphers.

The 'Cinematic Version'

Both the codemaker and codebreaker are given several modifiers. The codemakers's bonuses reflect his help in making the code, and the codebreaker's reflect the knowledge gained by hard work and spycraft.

Codemaker Modifiers:

Give the codemaker a circumstance bonus to his roll depending on outside help, in making a code (this reflects various factors, but mimicks a library aiding a research check.)
  • Power level of the Group:
  • A guild +2
  • A large and influential group +4
  • A small kingdom +6
  • A large kingdom + 8
  • The Empire +10
and assume he's taken 20 in making it-the result of extensive testing. This assumes a tested cipher-if not, roll normally. The result is the DC to beat in all papers where they use this code.


Give the codebreaker bonuses based on several things:
  • If he has broken this code before:+10*
  • His knowledge of the organization variable:**
And his access to coded materials:
  • Has negligible amounts:-2
  • Has some materials:0
  • Has a large amount:+2

To recognize information disguised by other methods, such as using invisible ink, bouquets of flowers, or rocks strewn across a log, an opposed check of the appropriate knowledge skills should be used in most circumstances.

Time Taken: 30 minutes on the first attempt. Success allows the player to read the document at the same rate as the intended party. A higher success will cut down on the starting time.

Retries: There are two options for retries:
  1. Retries are permitted only when new materials are found.
  2. Retries are permitted on a daily or weekly basis.
If a character gets more material done the same manner of encryptment (including same keyphrase or codebook), a successful roll vs. the new material also gives an understanding of the older ones. In addition to retries, new attempts are allowed when new material using the same means of encryptment (including same keyphrase or codebook) are found.

*This is a code that uses the same manner of encryption, but changes keywords or keyphrases (changing codebooks, for example, would constitute a new encryption). For example, During wars, an army would use the same codes, but change keywords daily. A codebreaker who has broken messages before from this enemy would get this bonus deciphering another message by the same people . This is the ONLY modifier which carries from one coded text to the next.

**Inside information, called cribs, can make or break a code. I adjudicate this on three factors: How much information the PCs have on the organization, what their capabilities are, and how much fun it would be to focus on information gathering. A series of +2 or +1 cumulative bonuses to the rolls, or allowing new retries would be appropriate.

Advantages: Gives a cinematic, long term feel that focuses on spycraft. Allows many natural opportunities for adventures.

Disadvantages: A lot of modifiers, players may feel that their own skill is useless compared to the modifiers involved. PCs may spend too much time focusing on information gathering rather then other adventures.

Why are the Cinematic DC's so high?

While skilled individuals can solve codes quickly, difficult ciphers take time. Code breaking can take weeks or months, and involve a lot of spy work. High DCs and Circumstantial modifiers reflect this.

Sample Cinematic DCs to use in descriptions.

  • DC 10: A standard MSC written by an amateur
  • DC 15-20: An MSC love letter written by a noble
  • DC 25-30: A 'simple' PSC or military MSC
  • DC 40: A secure military cipher based on a codebook, relying on several techniques to thwart codebreakers.
  • DC 50: One of the best military ciphers in the Empire, containing top level information.
  • DC 60: The Vigenere Square, used by one of the greatest mathematicians of the age.

Describing the Challenge

Here are some examples of how to describe the process of breaking a cipher in-game, based off the DC.

DC 15- a 'Ceaser Shift'

You read through the content and stare at the letters intently. While they SEEM to be random, some of the patterns look familiar and with a bit of ingenuity you experiment with alphabet shifts using frequency counts (High amounts of e's and t's), until the code is broken.

DC 30- A PSC

Even though Frequency analysis is difficult to use at this stage, there are still some ways to break the code. Since there's only a limited number of alphabets, you concentrate on finding letter repetitions, and the distance between repeated letter pairs. Soon, you know when the alphabets shift. From there, you divide the letter into three different alphabets, and the knowledge of the likely placements of several words in the report allows you to crack the rest open.

DC 45-A Military Cipher

It took serious effort to decipher the texts-the military relied on a very strict PSC. A combination of mathematical guesswork and a knowledge of how the military wrote their letters-always describing the weather at the end and consistent naming of several troop names and countries helped. If that trap to capture the codebook had succeeded, things might have been easier. As it was, one time, the PCs created a diversion only to make the next batch of missives describe the events-so that the PCs had probable knowledge of many words in the report. Eventually it was discovered that which set of encryptions were used depended on the phrases of the moon. After painstakingly compiling this information, the PCs now had their own codebook without the knowledge of the enemy. The trick then became using the information to their advantage without letting the enemy knowing the code was broken...

DC Epic:

Deciphering the Lich King's diary was a nightmarish piece of work. The numbers were without pattern, and it took a month to get letters to appear with any regularity. Worse, the Keyword for the Viginere's square was ridiculously complex, and your translation seemed to make no sense-the letters were a mass of random letters! Luckily, your historian determined Dreelix wrote in High Draconian using the common alphabet-notable for its consistent pattern translations into 8th century wood elf. But even after getting some written examples of Dreelix's methods of translating, the words didn't make sense! The translations came out as a discussion on Floral arrangements! Even the best of florists had nought to offer, and a month of studying extinct plants proved fruitless. Was it in the patterns of the petals, the month of the year in which it bloomed? You were ready to give up when you tried syllable counts in a night of drunken despair-it turned out that Dreelix turned the syllable count of words between hyphens into a single letter. Fiendishly tricky! From there it was a month of nothing but grunt work, translating accurately and counting the syllables. A dirty trick Dreelix, but after 9 months of grueling work now you had a set of directions to his treasure. Or is it?

Examples of Cryptography Aids in Military Inventions

Here are two devices in history used to encode messages-use them in your game, or as a way to think of more.

The Scytale- A Spartan invention, it resembles an octagonal wooden rod. The message is wrapped around the Scytale, and the formation of letters line up to be read.
The Codewheel- It consists of two rotating wheels, with symbols or letters encircling each wheel. Match a symbol from the inner and outer wheels, and you can encode or decode a message through holes in the wheel (the old AD&D computer games used these for password protection).

Ciphering In Game Documents

If you want to hand in-game documents that are ciphered, it takes some work. This is easy to do if you type it.

The DM's friend-Find and Replace

This function is invaluable. I use it to localize documents by adding spelling 'errors' and words common to a time, region, or writer. It can also code your document. This does require care, or you will ruin your document in short order. The easiest way to set a document is to assign each letter a number and a hyphen preceding it (any symbol will do.) Therefore, A= "-1", B="-2", all the way up to Z="-26.
From here, we have 4 steps:
  • Find and replace all the letters to the numbers and hyphens.
  • Assign the numbers a new letter.
  • Find and replace again, this time turning the numbers back into letters.
  • Finally, delete the hyphens. Viola!

If you want to give them a PSC in game, keep the different alphabets separated with different symbols-ie one a -, another a * or some such, and use Find and Replace commands like '*A becomes *26'. If you're doing a code with a visual element, make it physically, as that will probably be easier. Then type it up if needed.

Using Ciphers In-Game

Unless your players are interested in ciphers, it's best to leave it to character knowledge. However, if you want to get their brains a twirlin', here's a few puzzles-you may want to give clues, too. There are other resources online hidden as children's puzzles-check them out.

'White Noise'

The Cat is Brown

This is a simple pattern. Make the first/third/x letter on every line transmit the hidden message. The rest-the ABCs-is gibberish or a text on an innocuous subject. Add a clue like The Four become One, and may your players notice! Short messages will make this effect easier to handle, and easier to decipher in play.

Moby Dick predicted the Kennedy Assassination

As a side note, many books have 'hidden messages' when counting letters every 3rd line, 37 letters, page or some nonsense. It's quite easy to come up with a 'code' when you have a 500 page book, and this provides much fodder for conspiracy theorist...and a great way to increase paranoia in the campaign.

Psuedo English, or Pig Latin

The Cat is Brown
The At-Cay Is own-bray
Bru tthi ce wnos

Psuedo-Language can be surprisingly effective. Consider Pig Latin, with its three simple rules.
  1. If the word starts with a consonant and a vowel, put the first letter at the end and add ay. Cat becomes At-Cay
  2. If the word starts with 2 consonants move the first two consonants to the end of the word, and add ay . Brown becomes own-bray
  3. If the word starts with a vowel, add way at the end of the word. egg becomes egg-way.
Destroying words such as in, the, and as in this fashion is optional.
Note-while Pig Latin is 'easy', many variations of this are mor difficult. Written Ciphers have even more leeway. Here's an example, with only 4 rules:
  1. If the word starts with a consonant, take this consonant put it at the end of the next word (If this is the last word in a sentence, put this at the end of the first word instead)
  2. If the word starts with 2 or more consonants, take the beginning consonants from the word and put these on the end of the next word.
  3. If the word starts with a vowel shift the vowel one right to the next vowel (A becomes E, E becomes I, and so forth) and put this at the end of the next word.
  4. Repeat this entire process from the beginning with the sentence one more time.
The Cat is brown

Ebr atth sc owno (before step 4)
Bru tthi ce wnos (after)

Not an easy puzzle! Remove the vowel change and the repetition and we have
Ebr atth sc owni.

If this seems too easy or hard, change the rules until you have a challenge. You can also change the size of the words- The longer the word, the easier it will be to decode.

The Rail Pattern Message, Or String Pattern

The Cat is Brown

Rail Pattern is a classic children's puzzle. Separate the message into two lines, and read it in a W pattern, as though it were on a long string. Here's an example: The Cat is Brown becomes

Like Pig Latin, it's easy to make this much more difficult. You can add more lines, or have them read in a different pattern, such as a snaking one: T C A S B W N

Even simply reversing the sentence makes it much more difficult to grasp:



And keep in mind, this only addresses patterns-manipulating the text as though it were a string. Adding encryptment, even such as shifting every letter one space right on the second line, such as:

Makes it much more difficult to understand without help.

Phew! If you've kept up this far, congratulations! Hopefully, you've been armed enough handle the art of information secrecy to confound your players in play and out of play for quite some time. Until next time!