Just a bit confused as the PHB states that Druidic is used to write in code. Does that mean that Eyes of the Rune Keeper will allow me to read Druidic but not understand what it means or could I read it and understand it?
[RPG] Does Warlock’s Eyes of the Rune Keeper allow them to read Druidic
Eyes of the Rune Keeper does allow you to read Druidic (if you can spot it)
Druidic is a language, not a code or cipher
The only reason the messages are referred to as hidden and secret is that the language is because people who don't know Druidic find it hard to spot and can't decipher it without magic.
You need to pass a check to spot the writing first
Since you don't know Druidic, you must pass a check to even notice the writing. Note how spotting and deciphering are two different things in the description above. Once you spot it, the Eyes of the Rune Keeper kick in.
Eyes of the Rune Keeper is magical and allows you to read the writing
The description for all eldritch invocations says:
Eyes of the Rune Keeper, a magical ability by virtue of being an eldritch invocation, says:
Thus, if you are able to spot some Druidic writing, you would be able to read it with Eyes of the Rune Keeper.