Veni, Vidi, Vici

Veni, Vidi, Vici is the final main quest in Fallout: New Vegas if you choose to side with Caesar's Legion.

Quick walkthrough
After the Courier is asked if they are ready for the final fight and "yes" is chosen, they are moved to the Legate's camp. After some dialogue with the Legate, the Courier will storm the Hoover Dam, where their mission will be to kill the NCR General Oliver. The fight consists of breaking through four areas of the Dam with the various factions the Courier had befriended into helping them. The Courier will confront General Oliver and with a Speech check of 100, convince him not to fight the Legion. If the decision is taken to kill Oliver, the player heads to the final area, a room full of traps with a platoon of NCR Veteran Rangers. The general then waits for the player in a room up the stairs with several NCR heavy troopers. The player then leaves the room after killing General Oliver and his men, unless he convinced him to leave, at which point Lanius congratulates you for it, and for winning the Second Battle At Hoover Dam, and then shortly after, the game ends.

Detailed walkthrough
On the last section where the Courier is confronting General Oliver, there are many soldiers. First of all, the Courier must make their way around the force fields. After you do this, proceed to the second level. On this level, the general's guards must be killed, but keep an eye out for the many traps. Both corners of the office room on the 2nd floor have frag mines concealed in them that cannot be disarmed; the middle office sections are full of rigged shotguns and high damage explosives. Furthermore, some of the guards here have been known to carry anti-materiel rifles, which can greatly complicate matters for an unprepared Courier. After killing the guards, proceed to kill the general. Leave the room and be congratulated for spilling blood by the Legate and the game will end.

Behind the scenes

 * "Veni, vidi, vici" is Latin for "I came, I saw, I conquered," and was Julius Caesar's description of the short Battle of Zela that he fought against Pharnaces II of Pontus.
 * 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.

Bugs

 * 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.
 * When entering the Hoover Dam area with Rex and Cass or Rex and Lily as companions, both automatically go unconscious.
 * Raul randomly dies when attempting to enter Hoover Dam from the Legate's Camp. Waiting for an hour as soon as you walk through the door may prevent this.
 * The terminal to release the Legion Centurions inside the Hoover Dam Intake Tower 01 may not appear.
 * When on the second floor the game will freeze if trying to enter V.A.T.S. as soon as you walk up the stairs, though it may not if a valid target is present.
 * Sometimes General Oliver will get stuck in the debris at the top of the stairs, the player cannot kill him at this point and sometimes this will also cause the game to freeze.
 * If you choose to wait before entering legates camp, you might not be brought to the camp when you finally choose to go. Instead it will simply bring up the prompt, and then not do anything after choosing "yes".
 * During the confrontation with General Oliver, after killing him and all 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.
 * After killing General Oliver and the rest of his troops, the game will prompt you to exit through the first floor. The game may freeze (leaving you inside the room) when activating the door.
 * 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.
 * It is possible for an NCR ranger 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.
 * You may become stuck when trying to first talk to Lanius, as instead of the game reloading your location to the battle of hoover dam, you black in and out, and cannot move. May be caused by leveling up inside, or having Raul (or only Raul) as a partner following you inside at that time. Also, it may just randomly do it without leveling and reloading the beginning of the scene doesn't work to fix it.

Пришёл, увидел, победил