For the most part, plot twists on television have long been associated with the genre of drama. Climactic episodes and entire seasons often end with game-changing revelations, cliffhangers, and twists that set up stakes raising situations for all of the series' characters going forward. In recent years, however, sitcoms have decided to throw their hats in the ring, occasionally proving that they’re just as capable of sophisticated storytelling as their counterparts in the world of drama.

One of the sitcoms that has proven itself to be quite skilled in the mastery of the plot twist is The Big Bang Theory. The show has undergone a lot of change over the years, beginning as a more modest niche success that celebrated a very specific audience, and going on to become the most watched sitcom on television with especially broad and timely humor.

However, beyond the changes in tone and audience, the series has introduced countless characters and relationships, some of which have served better purposes than others. Some of these characters have also found themselves in surprising situations, either to end a season or to introduce a new conflict of sorts into the static world these characters live in. Because of this, some of these plot twists were executed much better than others, with some leading to instantly iconic episodes of television, while others were much better off forgotten.

Here are the 10 Plot Twists That Hurt The Big Bang Theory (And 10 That Saved It).

Hurt: Leonard wasn't faithful to Penny

The idea of a “will they, won’t they?” couple has essentially become a hallmark of the modern sitcom. It’s a way to hook viewers in for the long run, if they care about the thought of two couples getting together. Eventually, some lucky couples make it past the back and forth stage and make it all the way to the altar – just like Penny and Leonard did in the series’ ninth season.

The couple had plenty of ups and downs in the preceding eight seasons, most of which concerned their mutual insecurities and Penny’s inability to commit to a relationship given her lackluster personal history.

However, the series turned everything on its head with the surprising – and frankly idiotic – reveal that Leonard once cheated on Penny, kissing a woman while he was away on a research job – and continuing to work with her at Cal Tech to this day.

Saved: Professor Proton returns as Sheldon's Force ghost mentor

Introducing the legendary comedic actor Bob Newhart as the television icon that shaped Sheldon’s childhood, Professor Proton, may very well be the biggest casting coup the series ever pulled off. Professor Proton, also known as Arthur Jeffries, made a few scene stealing appearances on the series before he was sadly written out when Arthur passed away.

However, the series quickly proved that it knew better than to let such an icon go so quickly – and it found a truly inventive, series appropriate way to continue using him. Newhart has returned in the role of Arthur Jeffries on a few occasions, but now, Arthur visits Sheldon in his dreams as a Force ghost, serving as his Jedi master mentor to help him deal with situations he doesn’t know how to handle.

Hurt: Sheldon only proposes to Amy after being kissed by someone else

Sheldon Cooper has come a long way. By season twelve, he’s now married, physically intimate, and even engages in the occasional public display of affection. However, it was the storyline that took place at the end of the series’ tenth season that posed something of a disturbing problem for the character and his growth.

When Sheldon is visited by his former teaching assistant, Dr. Ramona Nowitzki, the woman makes her interest in him known once again – and even goes so far as to kiss him. Sheldon’s immediate reaction to the moment is entirely within his character – he gets up and runs away. However, what comes next is deeply troubling: he doesn’t just run away, but he crosses the country and immediately asks Amy to marry him – as if the decision to do so only occurred as a direct result of being kissed by someone else, rather than his decision that now was the right time.

Saved: Bernadette learns she's pregnant with Halley

It was a known part of Bernadette’s character: she had no interest in having children, regardless of what her friends, family, and loved ones thought. So the decision to have her wind up pregnant as a surprise was, admittedly, initially a troubling one, given the agency it took away from her character and the challenges it would pose to her previous strongly held convictions.

However, The Big Bang Theory managed to reveal Bernadette’s pregnancy in one of the most adorable ways it could have done so.

The season nine episode “The Valentino Submergence” includes this surprising twist in its final moments, as Bernadette reveals to a stray bunny – and the audience, but not Howard – that she is in fact pregnant. The sweetness of the moment – contrasted with Howard’s manic reaction to being bitten by the rabbit – adorably foretells the fact that Bernadette will be a great mother after all.

Hurt: Raj and Penny spend the night together

We’ve already noted that the “will they, won’t they?” romance has become a trademark aspect of most modern sitcoms. However, something that has become increasingly common, too, is the hijinks that ensue when two characters who should never, ever be together somehow wind up in bed together. For a little while, it can be funny, and even lead to some memorable moments. It shakes up relationships and makes everyone uncomfortable, which can lead to character growth and change.

However, on The Big Bang Theory, the decision to have Raj and Penny spend the night together couldn’t have been more of a misstep. It was also given the prominence of being a season ending cliffhanger, something that so mundane an act hardly merits.

Saved: Raj can finally talk to women

It was one of the longest-running gags on the series: Raj couldn’t speak to a single woman without consuming at least a little bit of alcohol first. He somehow managed to find his way into one long term relationship during that time by meeting Lucy, someone who suffered from severe social anxiety and was willing to go along for the ride in whatever form he needed – especially if it involved talking via texting.

However, the season six finale suddenly changed everything for Raj. Not only did he and Lucy break up, but he was so distressed over his split that he found, suddenly, he was able to speak to women without drinking at all. The alcohol very well may have provided him with some sort of placebo effect all along, but it was a momentous change in the series nonetheless.

Hurt: The comic book store is destroyed

Stuart’s comic book store has been a fixture in the series for most of its run. Countless episodes begin with the guys leafing through the bins of comics at the store and debating their latest nerdy topic of inquiry. Other episodes find them loafing around on the sofas in the seating area, debating other personal issues, and sometimes getting the lonely Stuart involved too. So when the season seven finale finds the store burnt down, it’s a huge shock to the system for the characters, and the series itself.

It also, unfortunately, leads to one of the longest running and worst chosen plots in the entire series.

Stuart moves in with Howard, Bernadette, and Howard’s mother, and serves as Howard’s mother’s caretaker, which is sweet at first. However, years later, even with the comic store back in action, Stuart is still living there, still intruding, still… Stuart.

Saved: The Wolowitz kids will never be seen on screen

Pregnancy storylines on sitcoms often yield comedic gold, as well as some genuinely touching moments. However, it’s impossible to deny the fact that, once the babies enter the world of the series, nothing is ever the same. Writers now have to account for young children, which can fundamentally change the group dynamics that have long been at work in the show.

The Big Bang Theory, however, found its own way out of this predicament. It was revealed early on after Halley’s birth that the baby would never be seen on screen – and when her little brother followed along, the same rules would apply. The babies would be heard vocalizing offscreen, but never once would a child appear on the series, preserving the status quo.

Hurt: Sheldon and Amy's first time

Few choices that The Big Bang Theory has made have been more ridiculous than the decision to devote an entire episode to Sheldon and Amy’s first time. This episode also coincided with the release of Star Wars: The Force Awakens, and found Sheldon forced to choose between attending the opening night premiere of the long-awaited film, or engaging in physical relations with his girlfriend for the very first time.

At its core, Sheldon’s pro and con approach to the decision makes sense. However, more troubling is the fact that this episode only further hammers home the idea that Sheldon can only be either a full-fledged nerd or a romantic being. None of the other male characters are forced to make this choice.

Saved: Leonard and Penny elope

Leonard and Penny haven’t exactly had the easiest – or healthiest – relationship. Their courtship was filled with seemingly endless ups and downs, steps backward and forward, missed opportunities and hidden feelings, and jealousy and concealed infidelities.

They’re not exactly the best couple in the world, but when it was decided that the two would say to hell with tradition and elope in Las Vegas, it made sense for them.

Nothing has been conventional about their relationship with one another, so it wouldn’t have made sense for them to have an elaborate, ornately planned wedding – especially when they’ve both always been so indecisive. Spur of the moment decisions suit them the best – even if they were then later forced to have a second wedding for the sake of their families.

Hurt: Raj enters into an arranged marriage agreement

Few characters on television could be described as hopelessly romantic to the same degree that Rajesh Koothrappali could be. He’s rarely ever had luck in love, but all along, he’s believed that it exists out there, somewhere. Even when he couldn’t talk to women without the aid of alcohol, Raj believed that love – real love – was waiting for him somewhere.

That’s what makes the series’ decision to potentially solve his lovelorn troubles by putting him into an arranged marriage so deeply disappointing. It’s always possible that arranged marriages can wind up leading to true love, but based on what we’ve seen of Anu so far, nothing about the pair suggests that they would be well-suited for one another. Raj deserves more.

Saved: Amy and Bernadette are introduced

In its earliest seasons, there’s no denying that the gender dynamics of The Big Bang Theory were fundamentally lopsided and completely flawed. Most of the issues that arose between the group of guys and Penny relied on tired gender stereotypes, and occasionally offensive judgments of her character.

The introductions of Amy and Bernadette definitely eased a lot of the earlier discomfort in gender dynamics. The ratio of male characters versus female characters is still slightly skewed, and skewed even more so when you account for all the supporting characters they interact with on a regular basis. However, there is now a female friendship group and support network, and female voices and opinions are heard and validated, too.

Hurt: Young Sheldon spoils Sheldon and Amy's future

There’s nothing wrong with a little foreshadowing every now and then. It makes eagle-eyed viewers feel curious, and inevitably like geniuses when they’re proven right about their theories. It also provides something for the general audience at large to notice in reruns after the inevitable event has occurred. However, there’s a difference between foreshadowing and flat out dictating the future that is going to happen. Unfortunately, the season one finale of Young Sheldon is guilty of the latter.

Following the episode of The Big Bang Theory that chronicled the events of Sheldon and Amy’s wedding day, an older Sheldon closes his narration of the Young Sheldon episode by revealing that he and Amy will have multiple children in the future.

It’s unlikely that these events will occur in Bang’s final season, and thus this provided a glimpse of a further future, but the bold choice still felt off, all the same.

Saved: Teller speaks as Amy's father

Sometimes, specific guest star casting choices come with added benefits that series can’t help but play around with. When it was announced that Amy’s parents would appear in the season eleven finale, played by Kathy Bates and Teller of Penn and Teller fame, it was immediately apparent that this was going to provide the series with ample hilarious material.

Boy, did they take advantage of it. For almost the entire episode, Teller plays his usual role, silent and dutiful and, in this case, henpecked, while Kathy Bates loudly steals the show. However, the real shocker comes right at the finale’s end, when Teller finally does the unthinkable and speaks on screen for one of the very first times.

Hurt: Raj and Howard almost end their friendship

Friendships inevitably change over time as people grow older and form families and other relationships. Responsibilities and priorities change, and personalities do, too. However, The Big Bang Theory took a truly upsetting approach to the concept of friendships changing when it had Howard and Raj on the outs for an extended run of episodes, when Raj told Howard he no longer wanted to be friends with him because of the fact that he was tired of being Howard’s punchline punching bag.

The two have always played well off one another, so to have them on the outs, no matter how justified Raj’s reasoning may have been, was incredibly hard to deal with. Thankfully, the two were able to make amends, and now share an even closer, more genuine, open friendship.

Saved: Leonard's father and Sheldon's mother couple up

Sometimes when a series puts two random characters in a surprising romantic situation, it just doesn’t work – for example, Raj and Penny’s night together. However, on other occasions, pairing two totally disparate characters can lead to some truly iconic reactions and interactions, such as when Leonard’s father, Albert, and Sheldon’s mother, Mary, spend the night together.

The potential ramifications of this romantic encounter could have been life changing for both Leonard and Sheldon, who are already quasi brothers in many ways. 

However, the series never continued to develop this relationship, perhaps due to Judd Hirsch’s other commitments at the time that prevented him from returning to the series to continue acting opposite Laurie Metcalf.

Hurt: Bernadette learns she's pregnant a second time

Bernadette’s first pregnancy was handled in a relatively amusing, adorable way. It never detracted from the overall storylines of the series but allowed for important conversations to be had and for characters to show new sides of themselves. However, Bernadette’s second pregnancy was handled with far less grace, particularly since this was now the second surprise pregnancy that Bernadette and Howard found themselves faced with – and so soon after little Halley was born, at that.

The series more or less had their hands tied in the matter, considering Melissa Rauch’s real life pregnancy at the time. However, there’s no way to overlook the fact that the storyline wasn’t handled anywhere near as well, or as meaningfully, as the first time around.

Saved: Sheldon runs away from home

Sheldon is a character whose life has been defined by routine and order, things he can control and feel comfortable with. The season seven finale, however, finds the familiarity of Sheldon’s world order suddenly upended, throwing him into a free fall as he struggles to accept the changing world around him: the comic book store is destroyed, Raj is in a new relationship, Leonard and Penny have gotten engaged… Things are changing, and Sheldon can’t handle change very well.

So what does Sheldon do? Something totally surprising for his character that truly left viewers with no idea of what was to come next: he took a train out of California and ran away from all of the changes he wasn’t ready to deal with.

Hurt: Zack and Penny have been married for years

Far too many shows have used the “we got married in Vegas and didn’t think it counted or we were drunk and didn’t remember” trope, so it’s disappointing when The Big Bang Theory, a show that can occasionally be pretty smart in its storytelling, decides to use that same cliché. Zack, Penny’s ex-boyfriend, was never the sharpest tool in the shed, but he was also by far the nicest of all the men she’s been with in the series, so it’s a good thing that it was him who Penny made the mistake of marrying, versus some of her other boyfriends.

It takes an entire episode for this hiccup to be resolved.

While it was definitely a fun way to bring Zack back into the action after his long term absence, there was really no point of wasting time on something so stupid.

Saved: Howard is chosen to go into space

It’s one thing to accept the fact that Sheldon, Leonard, Raj, and Howard are all accomplished, respected scientists within their field at one of the best research universities in the world. However, it’s another thing entirely to see one of them succeed in the way Howard did with the surprising reveal that he had been selected by NASA to go up into space.

The twist provided for some of the series’ most emotionally deserved moments, such as Howard and Bernadette’s spur of the moment rooftop wedding, and provided considerable amounts of hilarity as Howard checked back in with friends and family via Skype and proved that maybe he wasn’t the most mature astronaut out of them all.

---

What were your favorite or least favorite The Big Bang Theory plot twists? Let us know in the comments!