In a London circuit full of necessary new material nights, it has become an institution in just 18 months, run on the philosophy is that it is better to aim high and fall short, than not to try at all. There is a catchphrase to sum it up: ‘A failure!’ genial hosts Thom Tuck and John-Luke Roberts triumphantly cry after each act. ‘A noble failure!’ the crowd dutifully reply.

Experimentation is all. Tonight we witnessed a woman with a pumpkin on her head bashing herself with a hammer; the spirit of Saddam Hussein reincarnated in the body of a cat; four physical wrecks running lengths of the stage while knocking back vodka, lager and milk; a reading from an earnest academic paper about the effects of alien species on British freshwater life; and a trombone-playing troubadour in sparkly beard and flamboyant hat reading the speeches of Winston Churchill before the audience reenacted the Battle Of Britain with hundreds of cheap toy aeroplanes.

You will not witness the likes of this anywhere else, or, indeed, here again. The ethos is of unusual but semi-established performers trying things they could never do elsewhere – the very antithesis of the anodyne end of TV stand-up or the clubs which try to recreate that.

Tuck and Roberts – ‘not a conventional double act’, they are keen to remind us – are crucial in this; hosting without an apparent plan, celebrating in the awkwardness that sometimes creates, yet being witty enough to ensure their nonsense steers clear of the self-indulgent. In their compering duties tonight, they are aided with convoluted musical puns, courtesy of The Baptists, two-thirds of the comedy band whose leader, Johnny, was signed off on medical grounds.

Every institution needs its rules, and those at ACMS further underline the culture of creative endeavour. The audience may heckle, but only from a proscribed list. ‘We appreciate what you are trying to do!’ is allowed. As is ‘Tell us a joke! The ones you have been telling so far have been brilliant.’ Anything shouted out that’s not authorised – however funny – is slapped down with a brutally authoritarian: ‘Non-permitted heckle!’

Yet for all the caveats that much of the night ‘might be a bit shit’; it’s actually wonderfully entertaining overall. Certainly the community of like-minded souls helps, but jokes are funny, zany ideas are delivered with slapstick silliness, and fertile imaginations are allowed to run free. Plus, it’s a packed bill, so any failures – noble as they may be – are quickly scooted over.

The one thing that doesn’t fit in is the tried-and-tested. The second half here contained two broadly conventional stand-ups: Asher Treleaven – who complained his physical, nerdy material didn’t work in his native Australia – and slow-speaking circuit veteran Silky, with some quiet nonsense involving his guitar stand and a whimsical song. Nothing wrong with either (except, perhaps, for the old line ‘a groan is as good as a laugh – except in the bedroom’) but all a bit orthodox for this night.

Opening act Joanna Neary had mocked the rituals of stand-up, pretending that on her ‘course’ they had told her to gallop around the stage like Russell Kane or Michael McIntyre – regardless of her physical condition. This breathless performance perhaps fell into the ‘noble failure’ category, but symptomatic of this gig that she could do a gag about a theramin, in the assumption enough of the audience would know what that was.

Sara Pascoe did the ridiculous Saddam Hussein cat business, with mixed results, followed by Bridget Christie, for whom this night seems custom-designed, as she complains her mix of surrealism and gender politics makes her unbookable elsewhere. By her own account she did something ridiculous involving rice last month, but this time more straightforward, if decidedly quirky, stand-up.

Next Nadia Kamil, dressed as if she’d fallen out of the pages of Where’s Wally?, dared the audience to take her seriously as she read from the dry academic paper she’d brought along. The command to suppress laughter was, of course, enough to encourage titters around the room which she variously admonished or tacitly encouraged. It’s a technique Frankie Howerd mastered... but never quite like this. This section was closed by Ben Target and Matthew Highton leading the ‘bleep test’ athletic challenge that was so messy it needed an interval to clear up.

Afterwards, beautifully bonkers Tony Law revealed, in a chat show segment, how he helped found the city of Rome but failed to kill Hitler, leading into the more conventional stand-ups perviously mentioned.

William Andrews followed with his own take on the ‘comedy in the dark’ idea – and took the cliche that you could get laughs from reading the phone book, by doing the same with an anodyne Myleene Klass interview from a celebrity magazine.

Tom Bell also found inspiration from the newsstands, mercilessly – and hilariously – mocking Love It! before adding a Halloween twist to their HORRORscopes. Lou Sanders continued the October 31 theme, but from the pumpkin’s point of view, in a silly segment that was brief, but perfect length.

Finally, the resplendently dressed Matthew Kelly with gloriously odd non-sequiturs and convoluted bits of stage business, culminating in scores of planes flying between stage and audience in a memorably playful climax that sums up all that is joyous about ACMS.

It's more than a noble failure, it's a gorgeously flawed triumph.