Wild Card: Ace in the Hole

 is a quest in Fallout: New Vegas.

Quick walkthrough
After obtaining the key from Benny, head up to Presidential Suite. Search around and make it back to the elevator door, then Benny will talk through the intercom and stand you up. There is a speech option that requires a Speech 35. eventually the only text option is to threaten him, causing 4 or 5 guards come through the door. After surviving the attack, the next step is to go the 13th floor to search Benny's room (one of the guys you just killed will have a room key to get up there). Benny's elevator is the second on on your right, which will take you to a hallway. Go through the big double doors and the Yes Man can be found hidden in the back of Benny's bedroom in a secret room.

Detailed walkthrough
When you first enter the casino you can pass a speech check with Swank, allowing you to enter with your weapons. Next, if you you were able to pass the check and were able to keep your weapons, go past the front desk, across the casino floor and straight to Benny. Immediatly he will turn around and greet you. Then you will start to have a conversation with him. You will have many options when you first begin to converse, you can do the passive route and follow the responses leading to him giving you the Suite key and asking you to go up and wait in the room. The other route is to directly attack him. He yells for help from his 4 bodyguards and himself. Two of the guards will be carrying Silenced Submachine guns, the other 2 carry silenced .22 pistols, and Benny is using Maria, a unique 9mm Pistol. Killing them will be moderate, afterwards, collect your treasure from the dead bodies and move to the suite.

If you choose the passive route, go straight up to the presidential suite. Once in the room, check around for clues, grab whatever items you need, and return to the door, where Benny with be on the intercom, with a high speech you can persuade him. Otherwise, if not you will end up having to threaten him, then his guards will show up and attack you. This will be easier then the immediate attack seeing as Benny is not there to fight. You can find a 10mm SMG in the moderately locked safe in the room, or pick up a pool cue from the pool table if there is no other weapon around. Kill them and take the two keys they have. Leave the room back to the casino floor and go back out.

Find the safe behind the counter and take it, once you have, Yes Man should confront you, talk to him to activate another quest.

Behind the Scenes
The phrase "Ace in the hole" is used to describe something that can supply a sure victory when revealed.