The D & D Vortex is the sixteenth episode of the twelfth season of The Big Bang Theory.
Wil Wheaton is hosting a private Dungeons & Dragons game at his house with the participants being other famous actors, including William Shatner, leading to everyone wanting in on the game, with the condition being that they have to keep it a secret.
Sheldon and Amy are guests on Wil Wheaton's Professor Proton show, trying to explain their Super-Asymmetry theory, with William Shatner also appearing as a special guest. Sheldon gets so overwhelmed with excitement that he inadvertently pukes on Shatner.
The guys tease Sheldon after seeing the clip. However, Sheldon foolishly thinks that he'll get to meet with William Shatner again. He goes to Wil's house so he can offer Shatner an apology; while there, he hears what sounds like a Dungeons & Dragons game being played in the background. Wil closes the door, though Sheldon tries to peak inside, leading Wil to use the sprinklers to repel him.
Returning to Apartment 4A, he tells the others about it. They then decide to graph who else Wil may have invited. Howard, however, finds a picture on Instagram, showing Wil playing with William Shatner, Kevin Smith, Joe Manganiello, Kareem Abdul-Jabbar, and, much to their surprise, Stuart.
As he enters the kitchen at the Wolowitz house, Stuart finds Sheldon, Leonard, Raj, and Howard there; they are all furious that he attended Wil's D & D game night. He tries to hide it by saying he was at CVS, though they don't buy his lies, and start bombarding him with questions, causing him to breakdown. He then calls Wil to say that he's dropping out of the game because of all the pressure he got from the guys.
Later, Howard tries to call Wil, but his number is blocked. He eventually gets hold of him and pretends to be William Shatner, but Wil isn't fooled. While Sheldon is playing a Wild West game, Leonard gets a call from Wil, asking if he would like to fill in for Stuart; he agrees, but Wil tells him that he can't tell anyone else, particularly Sheldon. As Leonard, Wil, Kevin, Bill, Joe, and Kareem are playing, they find themselves dealing with a monster, and argue about how to deal with it: kill it or talk it to death, leading to Kareem asking Leonard what they should do. Leonard is practically enjoying himself.
Returning home, Leonard lies to Penny, saying he was at a "lecture". Penny assumes he was at "House of Pies" again. Leonard then lets it slip about the game, telling her about Joe Manganiello. In the Wolowitz kitchen, Penny tells Bernadette and Amy about how Leonard participated in the game; Bernadette confesses that she didn't see all of "Magic Mike" because Howard forced her to leave when he found out it wasn't about magic. Amy, however, has seen it about seven times. The girls then have a desire to play D & D again. The three women go to the set of Professor Proton and chat with Wil, who realizes that Leonard let it slip.
At the cafeteria, Leonard joins Sheldon, Howard, and Raj in a good mood, much to their surprise. Wil then calls Leonard to say that he's out of the game, much to his disappointment. He admits that he was a participant in the game, much to their disbelief. Leonard points out that they would've been secretive about the game as well. However, Sheldon realizes that, with Leonard out, there's now an open seat.
The four go to WIl's house, with Howard and Raj frantically knocking on the door; Wil opens the door and responds with a "No.", "No.", "No." directed at Howard, Raj, and Leonard, respectively, and a "Hell, no." directed at Sheldon. He feels that they just want in on the game so they can get close to his celebrity friends, making him wonder if they even like him for who he is. The guys promptly apologize, with Sheldon admitting that he never really considered Wil a celebrity, much to his annoyance.
Back in Apartment 4A, Sheldon, Howard, Raj, and Leonard are starting to play D & D. Still feeling bad about how they treated Wil, they decide to call him to come and play with them to make it up to him. However, Wil is already playing with the other celebrities, as well as Penny, Bernadette, and Amy. While playing, the women make small talk with Kareem, Joe, and William. Amy promises they won't let the boys know. Wil then suggests taking a group photo and sending it to them. The four of them then get the photo, which has Amy, Joe, Wil, Bill, Penny, and Kevin grouped together, and Bernadette standing next to the much taller Kareem, so tall his head is out of the picture, in the background. Leonard states that they deserve what they just got.