Had an idea for a plot generator for table top role-playing games last night. Probably best suited to an espionage or conspiracy theory game or a game set during the Renaissance. I was originally thinking of The Dee Sanction but Project Cassandra, Spy Master, Conspiracy X, Night’s Black Agents, 7th Sea and All for One: Régime Diabolique all fit the feel as do (I’m sure) many more I’ve not named.
Cardano Grille is a steganography cipher developed by Girolamo Cardano in 1550. It consists of a Grille with holes in it that can be placed over a letter to reveal a concealed message. Wikipedia has a write up of the Cardano Grille‘s history and method.
What you will need:
- A printer to print a grid
- A craft knife to cut out some squares
- A table of things to look up
- A book to do the looking up in
- A message template
Making a Grille
To make a Grille I printed a simple grid on a sheet of paper – card would probably be better for use at the table but for a prototype it was fine.
I used a 7 by 15 grid.
I cut a number of the cells out.
Using at the table
As a plot generator for a tabletop RPG:
- Take a Grille and place it over a page in the book – any orientation can be used
- Read the first full letter in each of the holes
- Look up what each of those letters mean and slot them into a message template
Example for a Modern Spy Game
Message Template:
There will be an [Letter 1: Incident] in [Letter 2: Place] involving [Letter 3: Person] which you should prevent. Secondary Mission: If possible retrieve [Letter 4: Thing] from [Letter 5: Agency] who are [Letter 6: Incident] [Letter 3: Person].
Look up Table:
| Letter | Incident | Place | Person | Thing | Agency |
| A | Blackmail | Berlin | Religious Leader | Artwork | CIA |
| B | Provocateur | New Orleans | Police Officer | Box | DEA |
| C | Brush Pass | Shanghai | Scientist | Weapon | GCHQ |
| D | Compromise | Tokyo | Criminal | Jewellery | FSB |
| E | Assassinate | London | Head of State | Briefcase | MI6 |
| F | Reconnaissance | Nassau | General | Diary | DHS |
| G | Poison | Amsterdam | Expert | Device | DIA |
| H | Defect | Athens | Agent Provocateur | Artefact | Special Branch |
| I | Discredit | Paris | Agent | Report | GRU |
| J | Wet Job | Budapest | Civil Servant | Disc | GIS |
| K | Mole | Cairo | Spymaster | Nuclear Device | BND |
| L | Black Propaganda | Venice | Diplomat | Prototype | DGSE |
| M | Disinformation | Kingston | Computer Programmer | Vehicle | NIS |
| N | Surveillance | Rome | Model | Bomb | Mossad |
| O | Exfiltrate | Washington | Controller | Cipher | NSA |
| P | Dangle | Bern | Actor | Document | SSA |
| Q | Interrogate | Sofia | Cobbler | Seeds | GRLS |
| R | Corrupt | Moscow | Business Leader | Jewel | KGB |
| S | Honeytrap | Istanbul | Journalist | Plans | DGSI |
| T | Black Bag Job | New York | Assassin | Database | FBI |
| U | Kidnap | Beijing | Child | Sample | DIS |
| V | Rolled-up | Tirana | Accountant | Money | SIS |
| W | Transport | Stockholm | Femme Fatale | Recording | FID |
| X | Sleeper | Oslo | Gangster | Stamps | DRM |
| Y | Steal | San Francisco | Double Agent | Microfilm | USSS |
| Z | Walk in | Hong Kong | Gang Member | Passports | DGI |
Opening “The Complete Plays of Christopher Marlowe” at page 441 and placing the Grille over the page I got the following letters:
A, O, D, O, S, H
This gives the message:
There will be an Blackmail in Washington involving Criminal which you should prevent. Secondary Mission: If possible retrieve Cipher from DGSI who are Agent Provocateur Criminal
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