The dark days on the set of That 70s Show

Cast of That '70s Show. Photo / Getty Images

It looked like the most happiest show on earth but the truth about what happened on the set of That 70s show will shock you.

Multiple rape allegations against one cast member, factions between actors, characters written out abruptly due to jail stints or alcohol and drug problems - the cast of 'That 70s Show' were a wild and troubled bunch.

The young group of actors that shot to fame in That 70s Show, the nostalgic hit sitcom which aired from 1998-2006, were all unknowns before scoring their roles. A teenage spin on the Friends model, the show is anchored around six kids who basically spend eight years of the 1970s cross-pollinating and hanging out. It was an immediate ratings success. The era hooked the parents and the cooler kids, while the whip smart comedy, easy chemistry between the cast, and frequent sex talk hooked everyone else.

Presented through a cartoonish '70s lens, the show represented a softer, rose-tinted reality. Archaic attitudes, indiscretions, and familial disarray are played for laughs, although the show also had a sharp tongue and surprising depths.

Topher Grace's comedic tussling with his hard-arsed father often reached nuanced moments; in one episode, rather than rebel against parental authority, his character Eric wonders if his father actually likes him.

The clumsy, hesitant teen romance between Eric and the literal and metaphoric girl-next-door Donna is one of the best depictions of young love seen on screen.

NOBODY LIKED THE STAR

If E! True Hollywood Story, is to be believed, Topher Grace was at odds with his young cast mates throughout the seven years he was on the show. Interviews, tabloid coverage, and subsequent podcast interviews show the other young males on the show -- Wilmer Valderrama, Ashton Kutcher and Danny Masterson -- were a tight knit crew. They ran late night (technically-illegal) poker games, frequented clubs, and were constantly photographed together. Topher was nowhere to be seen.

According to E!, the resentment stemmed from Grace: he was slated to be the star of the show (the early reliance around plot lines featuring Eric's family life bears this out) but as the other young actors and actresses became more famous, the show became a true ensemble. Grace left after the second-last season, and returned for a cameo in the show's finale. According to lore, he simply turned up, shot his scenes and, while the rest of the cast were hugging and celebrating and saying goodbye, he dashed to his car and drove back into the '00s.

The real smoking gun though: During his series 'Punkd', Kulcher pranked his other four young co-stars, but not Topher. Case closed!

SHOOTING DISRUPTED BY DRUGS

Wilmer Valderrama brought his own trouble to the set in 2004 by way of his wayward girlfriend, Lindsay Lohan, who threw the show's tight shooting schedule into chaos. She was booked to shoot a guest role, but was hospitalised for six days, for "exhaustion".

Her role in the episode was considerably lessened.

Scripting and shooting schedules were more seriously knocked off kilter when series regular Tommy Chong (of stoner comedy duo 'Cheech and Chong') was sentenced to nine months jail after a store he owned, Nice Dreams, was busted for selling bongs and other weed paraphernalia.

He missed two whole seasons of the show, inspiring an episode where the gang realise they haven't seen his ageing hippy character 'Leo' for a while, and attempt to track him down. Happily, Leo returned for the final two seasons of the show.

The show was in disarray from the start. Milas Kunis lied her way into the role of brash, bratty Jackie by claiming she was 18: a requirement for the audition. By the time producers and the network found out she was actually 14, they had travelled too far down the path, and were convinced she was right for the role.

Kunis, for her part claims she didn't lie, citing a technically: she'd told producers she'd be 18 on her birthday, but failed to specify which exact birthday. Again, case closed.

As far as misdeeds go, Kunis' was quite an endearing one. Sadly, things were a lot darker during the shooting of That 70s Show.

HYDE ACCUSED OF SEXUAL ASSAULT

Danny Masterson, who played the smart sardonic Eric Hyde, was recently accused of raping five women while he was a cast member on the show in the early 2000s. The LAPD are currently investigating the claims.

His rep issued a statement after the first three allegations were made public, denying the claims and arguing one "alleged incident" came in the middle of a relationship "after which she continued to be his longtime girlfriend" - while with another, "the LAPD interviewed numerous witnesses and determined the claim had no merit."

He also, strangely, suggests "these false allegations appear to be motivated to boost Leah Remini's anti-Scientology television series [Scientology and the Aftermath]."

Masteron is heavily involved with the Church of Scientology, as are all the women who have made claims against him.

At the Drive-In vocalist Cedric Bixler-Zavala claims his wife, Chrissie Carnell Bixler, was one of Masterson's rape victims.

He accused the Church of Scientology of attempting to silence accusers through coercion and extreme tactics.

"Our phones and computers have been tapped and the Church has been outsourcing private investigators and various thugs to follow and try and intimidate my family" he wrote on Twitter last November.

"If anything happens to my wife while I'm gone on tour then you'll know why."

Bixler-Zavala also received a cease-and-desist letter from Hollywood agent Marty Singer a year prior, after tweeting about Carnell Bixler's allegations.

The tweets were deemed "too suggestive."

"I never named Danny once", Bixler-Zavala wrote. "Marty use to rep Cosby. Need I say more?"

LAURIE'S TRAGIC ENDING

As Eric Foreman's manipulative older sister Laurie, Lisa Robin Kelly played the show's main antagonist; an innocent angel in her doting father's eyes and a conniving devil in everyone else's.

Grace played Laurie for Two-and-a-half seasons, before being abruptly written out of the show. Her character left suddenly midway through the third season to "attend beauty school", a plot line so uninspired it doesn't warrant further discussion. As the fulcrum to much of the show's tension, it was surprising that Laurie was so suddenly shunted, but her off-screen struggled shed further light on the matter.

"I had lost a baby," she told ABC in 2012. "As a result of that I lost it. I lost everything and I was abusing alcohol."

This interview came days after she was arrested and charged with domestic violence. Mugshots of the actress looking dishevelled and quite clearly under the influence spread and wide. This followed a widely-reported DUI charge eighteen months earlier, for which she was sentenced to twelve months probation.

"With 'That '70s Show' I was guilty of a drinking problem," she continued. "And I ran."

Kelly was brought back for a cameo midway through season five, and was reintroduced into the cast towards the end of the season. She lasted three episodes, before her character was replaced by actress Christina Moore. Kelly never returned to the show, and, aside from a one-episode guest role on Charmed in 1999, was never seen on television again.

The show's finale contains a sobering punchline at the expense of Kelly's prompt sacking, with her on-screen mother asking: "Speaking of daughters... has anyone seen Laurie?"

The year after her ABC interview, Kelly died from multiple drug intoxication. In August 2013, she checked herself into rehab to defeat "the addiction problems that have plagued her these past few years," as her agent, Craig Wyckoff, put it.

"I spoke to her on Monday," he explained in a statement, "and she was hopeful and confident, looking forward to putting this part of her life behind her."

Kelly died that Wednesday, aged 43.