Join the Khans

Join the Khans is a side quest in Fallout.

Detailed walkthrough
Upon entering the main building of the Khans' camp and talking to Garl Death-Hand, the leader of the Khans, the player character must tell him that they want to join, and "kick some serious ass" (choosing any other dialogue option will result in the Khans attacking them). Garl will then proceed to tell the player character that he is tired of his female slaves, and that the Vault Dweller must prove themselves by killing the slaves.

Doing so is easy, as they cannot fight back but will simply run away. However, the Vault Dweller must kill them before they leave the camp, as killing them outside the camp will cause the Khans to turn against him/her. Once they have been killed, Garl will name the Vault Dweller a "friend of the Khans" and grant him/her free access to the camp.

Rewards

 * 500 XP
 * -2 Reputation