Throughout its 12 season run, The Big Bang Theory cast enjoyed several iconic moments. Some that the fans appreciated most took place off camera, like when Kaley Cuoco and Jim Parsons would break character during their scenes, showing how close their connection was and how great the script also was.

As we're going to reveal in the following, moments of improv were few and far between. However, they did take place from time to time. We'll reveal a certain improvised moment that completely changed the dynamic of a character on the series. In addition, we're going to take a closer look at Kripke on the show, and how his speech impediment came to be.

John Ross Bowie was the man behind the character and fans have questioned whether or not he came up with the impediment, and if it is written into his script, or if the actor comes up with it himself organically as he's reading his lines? We have the answer and so much more relating to his character on the series.

The Cast Of The Big Bang Theory Rarely Improvised, But There Were Memorable Off-Script Moments

Going off the page was a rarity on The Big Bang Theory. Kunal Nayyer and others have revealed as such in the past.

According to Nayyar, the days on set were very tight, thus there really wasn't room for error or time to come up with improv work.

However, there are exceptions and one of them helped to shape a certain supporting character. Kevin Sussman's iconic "I love you" line to Penny in the comic book store was improvised by the actor. The moment was an eye-opening moment for the showrunners who really saw the potential in Stuart as a recurring character on the series.

Nonetheless, despite the improvised moment, Sussman revealed that he hardly ever went off the script due to the show's great writing.

He tells TV Store Online, "The cast doesn't improvise.

Because we don't need to, the writers are so good that if a joke doesn't hit, the writers will converge on the spot and within three minutes have it rewritten—so it is funny."

"The cast doesn't improvise. Because we don't need to, the writers are so good that if a joke doesn't hit, the writers will converge on the spot and within three minutes have it rewritten—so it is funny."

Like Nayyar, Sussman added that the shooting days were tight, and there wasn't time to improvise.

Kripke's Speech Impediment Was Not Written Into The Script And Improvised By John Ross Bowie

John Ross Bowie gave some extra details on his Big Bang character.

It is believed that Kripke's speech impediment was put in place to give the character a vulnerable side while still coming across as arrogant. It was Chuck Lorre that suggested the impediment during the audition phase, given that he didn't see enough vulnerability from the character. Co-creator Bill Prady then suggested the "liquid L" dialogue.

"He suggested a speech impediment. Bill Prady [creator] (who was also in the room, as was Lee Aronsohn) suggested a liquid 'L' – 'like Brokaw," Bowie tells Express.

Bowie admits he completely missed the mark with his speech, but it was still enough to land Kripke.

"What came out of my mouth was a horrible Elmer Fudd pastiche. Chuck laughed. I got the job."

As for the script itself, there aren't moments that tell Bowie when to use the speech impediment. That is completely improvised by the actor.

He revealed, "No, the impediment is not written into the script, I transpose it on my own."

For those that aren't aware, John Ross Bowie doesn't have any type of speech deficiency in real life.

Kunal Nayyar Was Not A Fan Of Raj's Mutism Around Women And Wanted It To Be Changed

Speaking of speech on The Big Bang Theory, Raj was given a certain trait he wouldn't be able to shake off until season six of the series. For Nayyar, this became frustrating more than anything else given that he couldn't contribute to scenes when females were around. The actor admits he'd look at the script for moments in which he couldn't speak and grew frustrated over it.

He reveals, "It was definitely frustrating because there were episodes where I knew I could contribute in ways [but] I was handicapped by the character's issue."

"There were a lot of scenes where I would sit and sit and sit and then I would have to whisper something and Simon got to tell the joke. And then, after a while, I would open scripts and see if I was in scenes with a female character,"

Thankfully, that would all change for Nayyar and he felt a great sense of freedom over it as an actor.