The Field Puzzle Formula
A field puzzle typically follows this pattern:
- Posted coordinates — Lead to an observation point
- Field variables — Numbers gathered from the location
- Formula — Combines variables to produce final coordinates
- Optional cipher — Field values may need decoding
Types of Field Variables
Counting
Windows, steps, benches, trees, bollards, fence posts, lamp posts
Dates & Numbers
Foundation dates, memorial years, house numbers, distances on signs
Letters & Text
Names on memorials, plaques, signs—converted using A1Z26 or word values
Patterns
Morse code in architecture, binary in window patterns, colours in sequence
Measurements
Compass bearings, paces to landmarks (less reliable but thematic)
Designing Coordinate Formulas
Your formula should produce valid coordinates from field observations:
Standard formula format:
N 51° AB.CDE
W 000° FG.HIJ
Variable Assignment Methods
Direct: A = number of windows on south wall
Calculated: AB = year on foundation stone − 1800
Word value: CDE = A1Z26 sum of name on memorial
Combined: FG = A × B (product of two field counts)
Integrating Ciphers with Field Elements
Pattern 1: Cipher Reveals Formula
Online puzzle gives the formula, field gives the values.
Cache listing has Caesar cipher that decodes to: "Count the lions, multiply by three"
Pattern 2: Field Reveals Key
Field observation provides cipher key for online puzzle.
"The Vigenère keyword is the family name on the large memorial"
Pattern 3: Encoded Field Elements
Physical features contain encoded messages.
Windows lit/dark encode binary; fence posts tall/short encode Morse
Pattern 4: Progressive Decode
Each field location reveals next cipher piece.
Stage 1 gives ROT key; Stage 2 gives Base64 text; combine to get coordinates
Complete Example
Cache Title: "The Historian's Trail"
Cache description:
"The old church holds secrets in its stones. Visit N 51° 30.000 W 000° 07.500 and observe carefully.
The final cache is at:
N 51° AB.CDE
W 000° FG.HIJ
Where:
• A = Number of arched windows on the east wall
• B = Century digit from the foundation stone date
• CDE = A1Z26 sum of the first name on the large memorial
• FG = Number of steps to the main door
• HIJ = Year on the sundial minus 1500
Example solution (your mileage varies!):
A = 4 (arched windows)
B = 8 (from 1842)
CDE = 051 (JOHN = 10+15+8+14 = 47, padded to 047... wait, need 3 digits)
Design tip: Ensure your field values produce correct digit counts!
Pro Tips
- Visit the location yourself. Verify all field elements are accessible, visible, and unambiguous. Take photos.
- Choose permanent features. Avoid things that change: parked cars, seasonal decorations, temporary signs.
- Build in redundancy. If possible, mention the same feature in your description so solvers can verify.
- Consider accessibility. Ensure the observation point is reachable by all cachers, including those with mobility issues.
- Check periodically. Field elements can change. Plaques get replaced, buildings renovated. Maintain your cache.