YOU may never have heard of Edward D Wood Jnr, a cross-dressing filmmaker, pornographer and author of pulp novels who was born in Poughkeepsie New York in 1922 and lived much of his life in Los Angeles.

But you will almost certainly have heard of his most infamous work: Plan 9 From Outer Space. It's regularly hailed as one of the worst films ever made, a critical judgement based on its plot, script, acting, direction, cinematography and on its use of silent footage (plucked from another film entirely) of a just-out-of-rehab Bela Lugosi doing that hammy thing with his cape.

None of this means that Plan 9 From Outer Space is worthless, however. But the value it has slowly acquired since its (brief) theatrical release in 1959 is not the sort that accrues to an epic flop-turned-neglected classic – Michael Cimino's 1980 film Heaven's Gate, say – or to knowing, low-budget trashfests like 1987's Surf Nazis Must Die, made by the cult Troma stable.

Loading article content

Instead, Plan 9's value is its honesty and its reputation as something approaching outsider art: Wood cared deeply about the films he made and truly believed he was heir to the greats. It's this passion, drive and eccentricity that Johnny Depp personifies in Tim Burton's 1994 biopic, Ed Wood, and which esteemed film critic David Thompson praises in his Biographical Dictionary Of Film.

"Edward D Wood Jr's films are bad," Thompson writes. "Yet today it may be easier to think that some droll, camp masquerade made them deliberately bad, instead of the [Tim] Burton line – that ardour, effort, soul and talent's void laboured over these pictures."

If you have heard of Plan 9 From Outer Space but haven't seen it, now's your chance. On Friday it kicks off the So Bad It's Good season at the Glasgow Film Theatre (GFT) where, along with Troll 2 and The Room, it forms a (sorry) troika of late-night terribleness.

"It's just a bit of fun really," says Allison Gardner, head of cinemas at GFT and co-director of the Glasgow Film Festival. "It's the tenth anniversary of The Room so we thought if we're going to show that, what other films would fit in? So we have Plan 9 and Troll 2, and then we realised there was a documentary around Troll 2 called The Best Worst Movie, so we're showing those as a double bill."

Despite the suggestion of the title, Troll 2 isn't actually a sequel to anything but instead a stand-alone 1990 horror film about a band of vegetarian goblins who want to turn people into plants so they can eat them. The Room, released in 2003, was once dubbed "the Citizen Kane of bad movies" for its shambling narrative and all-round bizarreness.

"The Room is really interesting," says Edinburgh-based filmmaker and horror aficionado David Cairns. "It's bad in ways that hadn't been thought of before, it's not bad in any obvious way. We say the performances are terrible but they're different from most terrible performances. They have their own specific quality. You'd expect bad acting to be inexpressive, but this is inappropriately expressive, which makes it really interesting to watch. It's always coming up with surprising new ways to be terrible – if it even is terrible. Perhaps it's brilliant in a way we haven't processed yet."

Gardner is open to suggestions from GFT regulars as to which other films should feature in the season, which rather begs the question: what's the difference between a so-bad-it's-good film and the other sort, which is just so bad it should be buried without trace? Is the presence of ardour, effort and soul the best yardstick, perhaps? Or are some bad films simply ahead of the curve, as David Cairns suggests? Who decides?

Those are the sorts of questions that can keep pub arguments going for hours, but happily for scholars of bad cinema there is something approaching a definitive list, thanks to people like Michael Medved and John Wilson.

In 1978, critic Medved published his book The Fifty Worst Films Of All Time (And How They Got That Way) and followed it in 1980 with The Golden Turkey Awards.

By the time he published The Hollywood Hall Of Shame in 1984, film publicist Wilson had launched the Golden Raspberry Awards and handed "Razzie" nominations to (among others) Xanadu, Jaws 3D, Raise The Titanic! ("It would have been cheaper to lower the Atlantic," producer Lew Grade famously quipped) and, long before it entered the neglected classic phase of its existence, Heaven's Gate.

On the back of their efforts, a kind of mini-industry has grown up, driven these days by the proliferation of social media, film fan websites and user-generated reviews. Now we take pleasure in loving something everyone else hates.

But there are some, such as filmmaker and critic Mark Cousins, who disagree with the whole notion of so-bad-it's-good, dismissing it as a kitsch marketing ploy. "I love genre cinema, but the very fact I love a film means I think it's good and not bad," he says.

"Everybody should have that much confidence in their own taste, so I challenge the premise that there's objectively bad stuff I could love. I think if I really like something, it must be because it's really good and I would say that of everybody's taste.

"If you love movies then you love it as a language, as a medium, and when people use it in a crap way, I hate it. There's another area which is the guilty pleasure thing, but I'm not sure I can think of a film that's crap that I love." Most of us can, however, which is why the so-bad-it's-good format is a winner with audiences. Everyone, I'll wager, has a favourite bad movie. Mine is Escape From New York, because any film with a character called Snake Plissken deserves to be loved. So go on, what's yours?

Plan 9 From Outer Space is at GFT on May 10 at 11pm. Troll 2 and Best Worst Movie are on May 12 at 2.15pm. The Room is on May 24 at 11.15pm. See for details.