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. It is suggested to get many stimpaks and/or super stimpaks and good weapons prior to entering this area. First of all, the Courier must make their way around the force fields. After you do this, you need to go to the second level. On this level, the Courier needs to kill the general's guards, 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. 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.

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.
 * When on the second floor the game will freeze if trying to enter VATS 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.
 * After heading up to the third floor to kill General Oliver, attacks will not harm or even touch him. Reloading the game from before you enter the room may fix this problem.

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.

Пришёл, увидел, победил