# Pseudo Roman Cipher

A while ago, I made this puzzle and gave it to my friend. But his comment was not so good. "This looks fine except it's not realistic", he said. I know he is smart but ... :( I don't want to believe that. Anyway, what do you think about this puzzle?

• In case it is not obvious, the story was created by me; he's an imaginary friend ; P .
– ACB
Commented Aug 18, 2022 at 5:00

# Step 1

Fill in the blank cells in the grid with:

..VII
IV.IV
.V...
VIV.V
III.V

where the letters are

the Roman numerals for the numbers indicated by the dots around the edges.

# Step 2

Breaking up the grid's contents (including the X's and circle in the original image) along the darker black lines gives:

XX VIII V XIV XV ⚬ XXVI V XVIII XV

or

20 8 5 14 15 ⚬ 26 5 18 15

Interpreting these as letter positions within the alphabet (and treating the middle circle as separator punctuation), this decodes to

THE NO. ZERO

# The title

"Cipher" is:

used with a double meaning: a method of encoding text, and as the number 0. (Both "cipher" and "zero" are derived from the Arabic word sifr.)

It's "Roman" because

It relies on Roman numerals.

But "pseudo" because the ancient Romans

did not have a symbol or word for the number zero, and did not use our modern 26-letter alphabet.

• @ACB: OK, have I got it now? Commented Aug 18, 2022 at 2:36
• Correct! Well done :)
– ACB
Commented Aug 18, 2022 at 2:45
• Rot13(Va nqqvgvba gb gur ernfba lbh tnir sbe pubbfvat gur jbeq 'cfrhqb' V gubhtug vg jvyy uryc fbyiref gb erzvaq bs 'bhgfvqr (fhqb)xh' (nygubhtu guvf vf abg n fhqbxh chmmyr, yvxr va guvf erprag cbfg) gb znxr frafr bs gur qbgf bhgfvqr gur tevq. Ohg V qba'g xabj vs vg urycrq lbh. Gvgyr jnf gur xrl :) )
– ACB
Commented Aug 18, 2022 at 3:00
• Your last spoiler also describes my friend's comment.
– ACB
Commented Aug 18, 2022 at 3:03