As nouns the difference between fudger and nudger
is that fudger is agent noun of fudge; one who fudges while nudger is one who, or that which, nudges.
nudger
English
Noun
(
en noun)
One who, or that which, nudges.
*{{quote-news, year=2009, date=February 8, author=Jeff Sommer, title=When Humans Need a Nudge Toward Rationality, work=New York Times citation
, passage=In Mr. Thaler’s words, “Sunstein would be the
nudger in chief.” }}