Roman Numeral Reference
I = 1
V = 5
X = 10
L = 50
C = 100
D = 500
M = 1000
Key rule: Smaller values before larger ones are subtracted (IV = 4, IX = 9, XL = 40). Otherwise, values are added (VI = 6, XI = 11, LX = 60).
Why Roman Numerals Work Well
- Common in the field — Found on buildings, monuments, clocks, graves
- Historical themes — Perfect for caches about history, architecture
- Direct coordinate use — Numbers translate directly to coords
- Universally known — Most people can read basic Roman numerals
Common Puzzle Patterns
Direct Coordinates
Coordinates written in Roman numerals.
N LI° XXX.CXXIII = N 51° 30.123
Field Reading
Read dates or numbers from monuments/buildings.
"The foundation date on the church: MDCCCXLII"
Formula Variables
Use Roman numerals in coordinate formulas.
"N 51° AB.CDE where AB = XIV + XXIII"
Hidden in Text
Roman numeral letters hidden in sentences.
"VIctory Is ours!" = VII = 7
Creating Your Puzzle
Use our Roman Numerals tool to convert:
Coordinates:
N 51° 30.456 W 000° 07.123
In Roman numerals:
N LI° XXX.CDLVI W 000° VII.CXXIII
Difficulty Variations
Easy (D1-D1.5)
- • Simple numbers (I-X)
- • Clear presentation
- • Numbers used directly in formula
Medium (D2-D2.5)
- • Larger numbers with subtraction rules
- • Field observation required
- • Mathematical operations on the results
Hard (D3+)
- • Roman numerals hidden in text (CIVIL = 157)
- • Non-standard notation (medieval variants)
- • Combined with other ciphers
Complete Example Puzzle
Cache Title: "Anno Domini"
Cache description:
"This church has stood since the time of kings. The foundation stone tells its story in the old Roman way.
N 51° AB.CDE
W 000° FG.HIJ
Where ABCDE is the year the church was built (read from the foundation stone), and FGHIJ is the digital root of that year, repeated."
The stone reads: ANNO DOMINI MDCCCLVI
Solution:
MDCCCLVI = 1856
Digital root of 1856 = 1+8+5+6 = 20 = 2+0 = 2
Repeated: 22222
Final: N 51° 18.560 W 000° 22.222
Pro Tips
- Verify field sources. If your puzzle relies on reading Roman numerals in the field, visit the location to confirm they're legible and accessible.
- Watch for zeros. Roman numerals have no zero. If you need zeros in coordinates, handle them separately.
- Consider weathering. Old inscriptions may be worn or partially obscured. Provide backup information if needed.
- Be aware of variants. Medieval Roman numerals sometimes used non-standard forms (IIII instead of IV).