Refinements are cool. They are the biggest new language feature in Ruby 2. They help you avoid some of Ruby's most dangerous pitfalls. They make your code cleaner and safer. Oh, and some people really hate them. Are Refinements the best idea since blocks and modules, or a terrible mistake? Decide for yourself. I'll tell you the good, the bad and the ugly about refinements. At the end of this speech, you'll understand the trade-offs of this controversial feature, and know what all the fuss is about.