Hardcore History is Carlin's forum for exploring topics throughout world history. The focus of each episode varies widely from show to show but they are generally centered around specific historical events and are discussed in a "theater of the mind" style. New episodes are released approximately every two to five months.

Hardcore History, which has more than 3 million downloads, was nominated in 2012 for a Stitcher Award in the Best Educational & Learning Podcast category.[4] In addition, Carlin has received the Best Classic Podcast in iTunes’ Best of 2014