What does Dill dare Jem to do?

In chapter 1, Dill visits his aunt in Maycomb and quickly becomes friends with Jem and Scout. After Jem tells Dill about the rumors surrounding their reclusive neighbor, Dill becomes fascinated with Boo and thinks about various ways to make him come out of his home. Dill then bets Jem that he will not run into the Radley yard and knock on Boo's door. Initially, Jem is reluctant to accept Dill's dare and contemplates knocking on the Radley's door for three full days. After Jem makes several excuses and stalls, Dill makes a mild concession and bets Jem that he will not touch the side of Boo's home, instead of knocking on his door. Dill then proceeds to mock Jem for being afraid, which persuades Jem to finally swing open the Radley's front gate and slap the side of Boo's home. After Jem slaps the Radley home, he boasts about completing the dare and feels accomplished.