IRL drama is drama that happens in real life, as opposed to Internet drama. IRL drama can cause Internet drama (ex. bitch cheats on her bf with another guy, then posts about it), and Internet drama can cause IRL drama (ex. post about Nazis reveals a friend's DAMN NIGGA or homosexuals and causes an IRL fist fight).
IRL drama is the ancestor of Internet drama. In the olden days before forums and blogs were established to help 16 year old girls vent about their meaningless daily drivel, they depended on word of mouth to flame each other so they wouldn't be confronted face-to-face and risk damaging their anorexic shells.
Through IM's, forums, blogs, and sites like Hi5 they can now lead entire flame wars without ever even seeing the other person, knowing who they are, and maintaining their safety while picking on someone 3,000 miles away.
A prime example of IRL drama would be the Holocaust, in which IRL Jew Jerry Seinfeld made a comment along the lines of "Adolf's momma is a real cunt". Understandably, Adolf Hitler wanted to get back at Seinfeld, and evened the score. This is not only an example of IRL drama, but also a prime example of Justice.