Duel on Bespin

The Duel on Bespin was a conflict that took place between Luke Skywalker and Darth Vader on Bespin, and it was here that Vader revealed to Luke that he was his father. After infiltrating the Imperial stronghold on Bespin, Luke attacked Vader when he revealed himself, but Vader mostly toyed with Luke for the majority of their battle. Despite this, Luke did occasionally suprise Vader by landing hits on him, and Luke did cause minor damage to Vader's suit when he landed a hit on Vader's shoulder blade.

After a duel that took them onto a thin walkway dangling over a chasm, Vader eventually sliced off Luke's hand and revealed to him that he was his father. He offered Luke a place at his side, but only if he turned to the dark side. Refusing, Luke instead allowed himself to fall into the chasm where he was picked up by the Millenium Falcon.