Spelling

publicly

No AL. Publicly is the one adverb that breaks the pattern.

  • publically

    publicly

    Just public + ly. No A.

The trick

Just add -ly to public. No A.

This is a genuine irregularity. Basic → basically, tragic → tragically, magic → magically—nearly every -ic adjective takes -ally. Publicly is the standard exception, which is why the wrong version looks more correct than the right one.

Now go leave out the A.