Wild Card: You and What Army?

 is a quest in Fallout: New Vegas. Yes Man sends the Courier to The Fort to activate an army of dormant Securitrons.

Quick walkthrough
This quest is started by talking to the security robot Yes Man in Benny's presidential suite on the 13th Floor of the Tops Casino.

Mr. House's Platinum chip is actually a key to a locked door on the floor of the weather station in The Fort. It will be on the body of Caesar if you kill him in the camp. Alternatively, Caesar may give you a quest to investigate the door under the weather station and destroy whatever you find there, if you come to meet him after killing Mr. House and installing the Mk. 2 securitron program. If you accept, he will let you enter, at which point you can either destroy the army or activate it; Caesar will assume that the rumbling of the Army activating was whatever you used to destroy it. If Caesar is dead, there will not be any charging guards.

To upgrade the robots, insert the Platinum chip. Otherwise, to stay a good character, simply fire one round into each of the 3 reactor modules.

Note

 * If you agree to "destroy" House's robot army, you'll get your stuff back inside the Weather Station. Once you're finished upgrading the Securitrons, you have the option to kill the 3 Legion guards. If you do this, the rest of the camp will be none the wiser and you'll be able to run around The Fort with all your gear intact. This'll make taking out Caesar and his guards a lot easier.

Bugs

 * Caesar can glitch when you talk to him. He will tell you that he wants you to do something but the only option was "I'm done working for you".