The Santa Simulation is the eleventh episode of the sixth season of the CBS sitcom, The Big Bang Theory, and it's third Christmas-themed episode. The episode aired on December 13, 2012.
Plot
Leonard is assembling a cardboard fireplace decoration for his apartment. He is amazed that he asembled a fireplace, though he did get apapercut.Then Leonard tells Penny that the guys are playing Dungeons and Dragons together because they haven't in a long time. Amy tells Sheldon that she always wanted to play D&D. Sheldon replies that she isn't invited because men at times have to get away from civility and break out into their primal selves. ells Amy about the game and she remarks that it sounds like fun. He tells her that this night is for men only. Howard tells Bernadette that she worked late so that they could be together on Saturday night. Howard tells her that if he doesn't come, then the guys will blame the failure of their night on her. Raj and Stuarthad planned to have dinner and see the Christmas lights in Grifffith PArk, but are even more excited about joining in the game. Their D&D quest starts with a Christmas gift given to Sheldon. Sheldon as usual is complaining about Christmas like the overuse of "tis" and "twas" He gets a scroll that descibes their quest that starts in a village of massacred elves and they must rescue their leader Santa Claus from a deugeon of ogres.Leonard thought a holiday themed quest would be great. Sheldon replies that that was lke a sandwich of grape jelly and petroluem jelly. . . Leonard wants both of them to have a great Christmas since he didn't have any when he was growing up. Instead of leaving Santa milk and cookies, they left research papers that in the morning were graded. Leonard has set up a holiday themed D&D game where Santa's village was attacked, Santa was dragged off and they had to rescue him. After going through stunts that included singing "Good King Wenceslas" and playing "Jingle Bells" on the bells, they finally reach where Santa is being held. Sheldon freezes Howard and Stuart, goes in, yells at Santa and then kills him. When Sheldon was five, he asked Santa do bring back his Pop-Pop, Meemaw's husband, who had just died and was his only relative that urged him to follow his dream into science. Santa brought him a set of Lincoln Logs. The others are completely shocked as they now know that Sheldon doesn't like celebrating Christmas as he was struggling to recover from such a traumatic family tragedy at the time.
That night Sheldon gets out of bed and finds Santa Claus leaving him presents and he apologizes for not bringing back his Pop-Pop though he said that his magic was limited. He also had something special for Sheldon. (Trains?) Because he left him for dead in the D&D game, Santa fired a cannon at Sheldon for his revenge. Sheldon quickly woke up from his nightmare, realising he shouldn't blame Santa for the fact that his grandpa cannot come back to life.
Earlier, Raj played his game too perilously and was killed on his first move. Penny pokes her head in tells the guys that the girls are going out and the guys get to see what they are missing. Acting like runway models, Bernadette is wearing a tight red dress from Century Forever and Amy is wearing a flowered dress from the sixties, actually showing some ankle, and new shoes. Penny is wearing a very short little black dress that got her out of some parking tickets. First they tell Raj that he can't came, then Penny pokes her head back in and invites him. At the nightclub, they discuss whether Raj should find a hook-up or a quality relationship. Amy announces that they should get him laid. He finds a hot girl at the bar, they talked for a while, he leaves her and finds that she gave him a phony email address. Raj complains that is really his fault since he fails for girls that are out of his league. He also mentions about falling for his friends hot girlfriends, Penny and Bernadette. Amy wonders about him falling for her and he says a definite "no". Penny and Bernadette urgently try to get him to change his comment about Amy and he keeps saying no. Amy starts talking about her earlier love life. Her first kiss was at twenty-two, but only before she returned some guy's medicine to him. She fell asleep at a frat party in college and woke up with more clothes on. She tells Raj that she knows what it's like to be alone and Raj agrees as they seem to connect. Amy immediately tells the girls that he's hooked and now they can leave obviously getting back at Raj.