Discover the wizard's weakness

There once was a wizard of great renown,
the truth of his power hidden away
held in the gems that lay upon his crown
so not even friends, his trust could betray.
Surprised one morning to hear a voice say,
Manfeld the Arcane, truly thou art cruel,
at midday today you and I shall duel.

The wizard smiled, confidence abound.
You must be a fool to challenge me so,
you cannot win without my weakness found;
it has been guarded well, you cannot know.
The challenger laughed, a laugh oh so low,
reaching into a sack hung at his thigh.
I have here your weakness, today you die.


What is the wizard's weakness?

Hint 1:

The number of lines and number of stanzas are important to the solution. The rhyme scheme and number of syllables are superfluous.

Hint 2:

The words in the poem don't matter at all for the answer. There's something else in the poem that can be extracted and decoded to an answer.

Hint 3:

Look for something that can be turned into binary representation.

• Don't know if these help, but rot13(gur eulzr fpurzr vf Eulzr eblny, zbfg snzbhfyl hfrq ol Punhpre; gur "gubh neg" vf vapbafvfgrag jvgu cebabhaf va gur erfg) Aug 22, 2020 at 11:59
• Not directly relevant, but good catch. I put the poem together over several days, and was never the best at following strict rhyme scheme (it's supposed to be iambic pentameter, but I think I messed that up). I chose rhyme royal because rot13(V arrqrq n frcgrg, naq eulzr eblny vf gur bayl bssvpvny sbez sbe n frcgrg V'z njner bs) Aug 22, 2020 at 13:17
• The sack at the challenger's thigh contains delicious chocolates. Aug 22, 2020 at 13:21
• I read the hint and thought: "Oh this is obvious" Tried it out: "Maybe not" Aug 24, 2020 at 21:19
• In the first line it says 'maths' if you exclude the repeating letters and you look at the first letters
– PDT
Aug 24, 2020 at 21:59

The wizard's weakness is:

IRON

To find this out, note the line 'held in the gems that lay upon his crown' - this suggests...

...we will find the answer concealed in the first letters of each line, as these letters could poetically be seen as the 'gems' that 'crown' each line.

What we then need to do is...

...equate each upper-case letter with a '1' and each lower-case letter with a '0'. This gives us two 7-digit binary numbers (one for each stanza): 1000110 and 1100101.

These numbers are equivalent to the decimal numbers 70 and 101, respectively. If we look these up in an ASCII table, we see that these correspond to the characters 'F' and 'e'.

And of course if we put these together, we get...

Fe, the chemical symbol for the element IRON! Presumably then, the challenger's sack contains an iron weapon of some kind, possibly a sword.

As a bonus:

This conjures up an allusion to a current (and very good) series of children's books by Cressida Cowell, The Wizards of Once, in which iron is the one material on which the wizards' magic cannot work. Worth a read, whether you have kids, are a kid, or neither!

• Darn, I counted the number of words instead, used the same method and got “2p”.... great find! Aug 25, 2020 at 14:50
• I'll need to check out that book, always interested in new fantasy series. I was actually thinking of Kingkiller Chronicle where fae magic has the same weakness. Aug 25, 2020 at 15:06

My answer is aqua fortis which is an alchemic name for nitric acid. This acid could dissolve minerals and is mineral in nature itself, being inorganic.

The clue was the 7 7 structure of the stanzas which are the nucleon counts of protons and neutrons in nitrogen, being the 7th element (hence proton number is 7) and mass number 14.

• No, although I would be interested in the logic that leads to that. I don't know anything about chemistry really. Once the trick is figured out, getting the final answer should be really simple. Aug 23, 2020 at 1:39
• I have edited my answer to include the logic. I should have realised my answer was too elementary to be right. :) Aug 23, 2020 at 2:01
• Interesting :) Even more so because the answer I had in mind rot13(vf na ryrzrag ba gur crevbqvp gnoyr) Aug 23, 2020 at 2:22

Phosphorus... Or maybe zinc? First letters of lines almost say 'mass thirty'

• Looking in the right area, but wrong conclusion Aug 23, 2020 at 3:14