Friends proved to be an instant hit, and that holds true today all these years later. In terms of memorable moments and storylines, that show had so many, and what makes things that much better is the fact that a few moments were completely improvised.

In the following, we're going to take a look at memorable moments that featured the cast going off script. One moment in particular was especially hilarious given that the main cast teased Matthew Perry on his flub - and the moment actually aired.

We'll reveal exactly what went down, and how the show felt about guest stars trying to improvise. As it turns out, outside the main six, going off script while on the show was not the best idea, and discouraged by those behind the scenes.

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jennifer aniston as rachel
A screenshot photo from Friends showing Jennifer Aniston as Rachel sitting in black at the coffee house.
via YouTube

Friends just did things differently. In fact, some of the show's best and most memorable moments were completely unscripted. The show loved to improvise and edit scenes, it was all about getting the best laugh possible.

We saw several iconic improvised moments along the way. Among the most memorable includes Rachel's "world's worst hangover' line after marrying Ross. This was added in by Aniston, and got a phenomenal reaction by the crowd on-hand. Matt LeBlanc also had iconic moments of improv, accidentally falling when reaching for the phone, he was even hilariously trolled by Matthew Perry which also ended up making it to the final cut.

RELATED - David Schwimmer's Unscripted Moment Would Lead To The Most Iconic Line In Friends' History

Looking back, Matthew Perry was considered among the elite when it came to improvising. However, during this particular moment, it was the cast that turned the tables on Perry after he legitimately flubbed his line. The moment made for great TV and one that the entire cast took part in. Ultimately, it was used by the showrunners for the actual episode.

After Matthew Perry Flubbed His 'Blue Blazer Back' Line, The Friends Cast Continued The Scene And Trolled Chandler

The line was supposed to read, "Donald Trump wants his blue blazer back", but it turned into, "Donald Trump wants his blue blazer black." Ross, Joey, Monica and Rachel all look on puzzled, and pounce on the situation. Cox hilariously says, "you messed up, you're stupid."

The unscripted moment has thousands of views on YouTube, and clearly, fans had a blast with outcome, especially knowing that it was reworked by the cast.

One fan writes, "The brilliant improvisation and great chemistry between the cast explains why the show was such a phenomenal success."

"I can’t imagine how hard the cast laughed at this when they saw it for the first time thinking that this was going to be a blooper then realizing that it was used in the show!"

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Clearly, the cast had a great time on the show, and that was also evident through the many bloopers as well. However, it seems like the show wasn't as flexible with guest stars, at least that's according to Jennifer Coolidge and her experience on Friends, playing the role of Monica and Phoebe's unwanted friend.

Guest-Stars Didn't Have The Same Flexibility Improvising Lines On Friends, According To Jennifer Coolidge

Jennifer Coolidge on the red carpet
Jennifer Coolidge on the red carpet
via Instar

The chemistry between the main six was strong on-camera, but the same held true off of it as well. However, when it came to improv work, others didn't have the same flexibility. Looking back at her guest role on Friends, Coolidge tried to pitch an improvised moment but the showrunners weren't having it.

Coolidge reveals, "Sometimes I think people want to hear my ad-libs when I get on a show, and they really don't. Sometimes I come in and throw some lines, and they come up and say, 'You know, Jennifer, we're just going to stick to the script.' That was a serious show."

"The vibe was pretty serious," she continued. "I don’t think they wanted my input, and I could really feel that…sticking to their own stuff. So I didn’t have the guts [to push]."

Coolidge called the experience 'intimidating', though she was able to improvise her dance alongside Matthew Perry during her final scene on the show.

"I have to say, I was kind of intimidated, even though I knew Lisa because she was in a comedy group. But I didn't know the rest of them, and I was very intimidated because they were all so attractive and had it going on."

"The only thing I improvised was they wanted me to dance awkwardly, so I felt like I had a natural ability to dance that way. I think that was the only time they didn’t give me direction; they wanted me to say the lines and call it a day."

At the very least, Coolidge got to experience the iconic sitcom, even though it might not have been what she expected.