No Gods, No Masters

 is a quest in Fallout: New Vegas.

After clearing the Hoover Dam, the Courier sets forth to the Legate's Camp for the final confrontation against Caesar's Legion.

Detailed walkthrough
To do this you may go in guns blazing or simply take out the first guard and disguise yourself then as you go up the steps you may want to save. You have two paths: one fight your way through legate leader or, if you have a speech skill of 100, talk your way out (have in mind he is a very tough enemy but you get the bonus of his weapon and his mask for killing him). Once done proceed to the gate you entered through and once you walk up to it it will explode and heavy NCR troopers will walk in as well as the general who will talk to you (notice there is a fog behind the gate). You have a few options which will all clear the fog revealing your army with Yes Man leading it. Depending on your choice they will either kill the NCR or they will just let them walk away. Afterwards Yes Man will tell you you've done well and say he's going to get an upgrade to be more assertive. Note that once you speak to Yes Man, the credits will roll telling the story of how you have done. After the credits are over you will be reset to your last save. Therefore killing the legate and taking his mask, is completely useless.

Bugs
If you fast travel out of the Legate's camp before your task is complete, two things will happen. 1: You will not be able to fast travel back and 2: There is a glitchy force field that blocks you from entering the Hoover Dam. Still trying to figure out how to fix this. I have not updated yet so it is possible that fixed it.