The Lasso of Truth forces people to tell the truth. It was forged by Hephaestus from the Golden Girdle of Gaea that Antiope had once worn. It is able to restore people's lost memories get rid of illusions or cause illusions to those it holds and heal the holder's body cure insanity and protect people who are in close proximity to it from magical attacks. In the golden age version the lasso could also take on a rigid form and hold people aloft from a great distance away. During these eras, the lasso also forced those who were bound by it to act as the holder demanded. This trait also affected Wonder Woman. A non-combat application of the lasso is that it can be used to change Diana's clothes as long as those clothes are "in the right frequency" as the lasso. Although this was a plot device used more often in the golden and silver age in has been used on occasion in modern comics as for instance one time Diana transformed into a Miss America costume. The lasso is essentially indestructible, and can be offensively used in combat to incapacitate, and even attacking their souls.
Later, as a healer tended to Diana's battle wounds, she noted with confusion that Diana's wounds had healed completely. Diana then visited Trevor in his cell, asking him about the outside world. Due to his words, Diana decided to sneak him off the island and confront Ares herself. She snuck into the island's tower and stole the god killer, along with an Amazon shield, the Lasso of Hestia, and a special set of battle armor. She broke Trevor out of his cell and took him to the island's dock, where she was intercepted by her mother. To her surprise, Hippolyta allowed Diana to leave, gifting her Antiope's tiara. She then warned Diana to be careful, mournfully telling her that the world of men did not deserve her.