TL;DR: respond_to? will return false for protected methods in Ruby 2.0 Let’s check out how protected and private methods behave in Ruby. After that, we’ll look at how Ruby 2.0 changes could possibly break your code (and what to do about it). Method Visibility In Ruby, we have three visibilities: public, protected, and private. Let’s define a class with all three: class Heart def public_method; end