Break through four areas of Hoover Dam and make your way to General Oliver.
Confront General Oliver and either kill him or convince him to not fight the Legion. It takes a Speech check of 100 to convince him to stand down.
Cross the dam and make your way to the western power plant.
(Optional) Take out the snipers who've taken up position in the western portion of the dam.
(Optional) Release the waiting Legion reinforcements inside the intake tower.
Find the enemy commander, General Oliver.
Kill General Oliver and the soldiers guarding him.
Return to the Legate and tell him that General Oliver has been driven off.
Return to the Legate and tell him that General Oliver has been killed.
Behind the scenes
"Veni, vidi, vici" means "I came, I saw, I conquered," Julius Caesar's description of a short war that occurred in what is now Turkey.
If Arcade Gannon is following as a companion, he will leave upon arriving at the Legate's camp. Attempting to talk to him again will result in him saying "Why don't you make like Odysseus and get lost?" This is a reference to Homer's "The Odyssey" in which Odysseus treks 10 years across the Aegean Sea, trying to return to his home island of Ithaca following the Trojan War, but gets lost and side-tracked numerous times along the way.
PCPlayStation 3Xbox 360 It is possible for General Oliver Lee to become friendly in the office trap area. He will flee from the player, making the objective of killing all NCR soldiers much more difficult.
PCPlayStation 3 During the confrontation with Oliver and his troops the player must navigate through a room full of mines, tripwires, and other traps. If the player quicksaves and quickloads all the mines previously detonated will detonate again.
PlayStation 3Xbox 360 After leaving the Legate's tent, the gate to the dam will not open and you are unable to fast travel thus you are unable to complete the Veni Vidi Vinci quest and finish the game.
PlayStation 3Xbox 360After killing General Oliver and his guards, the quest will not move on to tell you to exit the room. Despite searching every area for any lingering enemies, no red tick(s) will appear. Simply load a save from before the conversation with General Oliver and try again.