Audiences are encouraged to stick to well-beaten tracks , and critics seem quick to form a consensus over ' must-see' productions, but the spirit of the unexpected is not yet suffocated Who would suspect before the wires began to hum, for instance, that a one-man performance combining magic, psychology and story-telling would be such a hot ticket, asks PETER CRAWLEY

IT IS NOT enough to succeed in Edinburgh (to borrow Gore Vidal's maxim). Others must fail. This is the crueller impression you might get along the cobbled streets of the Royal Mile, thronged with performers and slick with promises, where, you are assured, every show is unmissable. Competing against almost 2,700 other productions, every performer can point to a four- or five-star review, often from a suspiciously unfamiliar source, and though star ratings have never seemed like a hard currency in Edinburgh they now seem entirely devalued: "Free show. Five stars." Towards the end of the festival last week, the sales pitches had become wearier, and oddly realistic: "Free comedy," someone said to me. "I can't make you come."

Although it resembles a busy souk for the Edinburgh Festival Fringe, the path threads through several of the city's simultaneous festivals, stretching from the Edinburgh Castle (where the Military Tattoo booms out its salutes each night), past the humming headquarters of the Edinburgh International Festival, and splintering away towards several sepulchral Fringe venues. Among this bustle, everyone is looking for a way to stand out. Only a fraction ever will.

Now in its seventh year, the Culture Ireland showcase has long been aware of the risk and the potential gains of presenting Irish artists at Edinburgh, as well as the necessity of creating an advantage for the authors and performers it brings there. But this year, presenting a slightly smaller showcase than in previous years, the State agency for the promotion of Irish arts abroad seemed to concentrate less on the vagaries of the Fringe and, for its theatre strand, to put all of its stock in the more orderly EIF. For Culture Ireland, the Fringe was always a bit of a gamble, but risks have been mitigated through carefully cultivated relationships with quality-assured venues such as the new writing theatre the Traverse and the similarly curated Dance Base, and networking events with Irish delegates and international producers.

This year, it seemed to play it even safer. With CI's assistance, four dance companies returned to the security of Dance Base; Tumble Circus performed their confessional acrobatic comedy in the E4 Udderbelly; and Jack L performed at the Acoustic Music Centre. At the EIF, the Gate presented its enormously well-received production of Watt ("Beyond perfection . . . Five Stars" - the Scotsman); Silviu Purcarete directed a visually impressive but tediously shallow adaptation of Gulliver's Travels for Radu Stanca National Theatre of Sibiu (for which Shaun Davey composed its score); and singer and performer Camille O'Sullivan appeared in a unique collaboration with the Royal Shakespeare Company on a retelling of Shakespeare's poem, The Rape of Lucrece, which, she gamely warned us, "may contain songs".

It has been a canny investment - Watt shows no signs of slowing down and the Gate seems likely to return to the EIF, and last weekend, following glowing reviews, O'Sullivan was presented with a Herald Angel Award for her performance - but it also seems rather risk-averse. O'Sullivan is already an Edinburgh star and the imprimatur of the RSC, the Gate and the EIF makes such performances seem like a triumph of the overdogs. This only matters to those who associate Edinburgh with taking a chance and making new discoveries, which made it all the more heartening to see Fishamble: The New Play Company's production of Sonya Kelly's The Wheelchair on My Face receive another top award, the Scotsman's Fringe First, last week. As one of three Irish productions to attend the Fringe without Culture Ireland support, Fishamble's success with Kelly's autobiographical comedy of a shortsighted childhood had the reaffirming sensation that an offbeat idea with a modest but imaginative production could stand out among the throng. It also appealed to the better nature of the festival.

Writing recently in the Guardian, the comedian Stewart Lee excoriated the commercialisation of the Fringe, in which, he argued, higher costs were pushing independent and innovative artists out of the programme and shrinking the space for experimentation. It was easy to see his point: the Fringe has best been characterised by the daring of both its artists and its audience. "Historically, the Fringe has represented a unique middle ground between what artists want to do and what people might suddenly find, unexpectedly, they want to see," Lee wrote.

Audiences may be encouraged to stick to well-beaten tracks and established critics still seem quick to form a consensus over "must-see" productions, but that spirit has not been suffocated. Who would suspect before the wires began to hum, for instance, that a one-man performance combining magic, psychology and story-telling would be such a hot ticket, or that a South African adaptation of a Strindberg classic would sell out, or that a verbatim piece based on interviews with children and performed by adults in business suits would become such a talking point? "A lot of people would probably term Bullet Catch 'new work' as opposed to 'new writing'," the new director of the Traverse, Orla O'Loughlin, says of Rob Drummond's brilliant piece, whose structure leaves large spaces for improvisation, participation and risk. "But if you ask Rob Drummond who he is, he says that he's a writer and that's why he's in our programme."

That was true of a number of this year's 19 productions at the venue during the Fringe. "I think there's a sense of getting down to the bare bones of things, of revealing things for what they are, in getting to the core of what a belief system is, or relating - as directly as possible - what an experience has been," says O'Loughlin.

Like Bullet Catch, Kieran Hurley's excellent story, Beats, set during the 1994 crackdown on Britain's rave culture, made itself into a small lens for bigger social issues, while Daniel Kitson's dizzyingly self-reflexive piece, As of 1.52pm GMT on Friday April 27th 2012, This Show Has No Title, involved just Kitson, alone on stage, reading a play about the making of a new Daniel Kitson play, which skilfully and comically preserved its hall-of-mirrors approach without disappearing up its own conceit.

Presenting work outside the organisation of such curated venues as the Traverse, the Irish director Donnacadh O'Briain decided to create his own instead. A self-contained cube, in which 12 individual booths peered into a performance space, it replicates the structure of a peep show, for a series of short plays about sex, entitled, fittingly, Peep.

This was O'Briain's first time back at the Fringe with his London-based Natural Shocks company since 2005, following a dismal time spent chasing audiences for an otherwise well-reviewed show in an awkward time slot.

"I just worked incredibly hard, was incredibly poor and not terribly happy," he recalls. "I thought, I'm not doing that again unless I've got enough money that I can live happily and I've got something to really push."

With Peep, whose setting and substance generated buzz among audiences, media and promoters, the decision to return appears to be working out. "It's the biggest arts market in the world," says O'Briain, who had been in conversation with several producers and presenters about staging the work elsewhere, although as of yet nothing has been locked down. "Edinburgh is too mental to actually do proper negotiations here anyway," he says. "It's really about starting relationships. September is about commitment, I suppose."

It isn't that Edinburgh is shy on commitment - indeed, Christine Sisk, the chief executive of Culture Ireland, pointed out that Camille O'Sullivan's involvement with the RSC had grown out of long-developing relationships, and both Sisk and the Traverse, which featured no Irish work for the first time in several years, hoped to restore their association in the future - but its maddening allure is still one of a city guided by whims and impulses. That's why a cheering show about childhood myopia can come into sharp focus on the Fringe, or a cabaret star can come to deliver a Shakespeare poem with stately presence and raw emotion at the EIF.

To the sceptical outsider, Edinburgh will always looks like a place where success is unlikely, but to the true believers it is a place that will always favour unlikely successes.

FIVE RIGHT ON TARGET

BULLET CATCH

Beginning with a story of a Victorian conjuror who died performing this infamous magic trick, writer-performer Rob Drummond skilfully performs his own illusions with one volunteer, but artfully drives deeper than ta-dah moments. Teasing out the fragility of trust, fate and free will, it resolves not so much in a grand finale (although that is nerve-wracking) as an affirmation of the bonds between people.

MIES JULIE

Yael Farber's searing adaptation of Miss Julie transposes Strindberg's classic power struggle to contemporary South Africa, bringing new life and greater complexity to the play. Instead of the imperious Julie being undone by her own sexual desire, the Farber's sinuous performers are tragic inheritors of the apartheid past, slipping into an unending power struggle with stunningly brutal consequences.

MEINE FAIRE DAME - EIN SPRACHLABOR

This amusing but distracted piece based on My Fair Lady from Swiss auteur Christoph Marthaler and Theatre Basel features an assortment of oddballs in a 1970s language lab where Marthaler piles on musical and intertextual references including nods to Frankenstein, Mozart's The Magic Flute and Wham's Last Christmas. Not bloody likely . . .

BEATS

Set in 1994, against the Criminal Justice Bill's crackdown on rave culture in the UK, Kieran Hurley's monologue, delivered over an era-appropriate DJ set and video design, gives a poetic and vividly detailed perspective to a teenager clashing with a policeman, as two visions of society and solidarity come crashing together.

THE RAPE OF LUCRECE

Camille O'Sullivan delivered Shakespeare's tragic poem of lust, violence and politics with careful poise, on a stage lined with texts and ruined art works, while threading several verses into Feargal Murray's brooding score. A refreshing style for the RSC, it sometimes grazed against Nick Cave's Murder Ballads, but O'Sullivan made it something more moving, passionate and mythic.