The beauty of Rule the School, returning for its third series, lies with its timelessness. Its central premise, forcing teachers to trade places with pupils, retains potential to go on generating excitement and entertainment in theory forever. By taking as its foundation a universal fantasy, the programme will surely continue to ring true as long as there are school gates through which generations of five-year olds must pass.

All the motifs of childhood – the tedious communal gatherings in assembly halls, the awkwardness of stepping up to participate in desperately unappealing tasks in front of all your peers, the pressures to behave, the pressures to misbehave – they’re all here, packing as much emotional resonance as they ever will. But better still, thanks to the similarly enduring conceit of role reversal, they are rendered on screen all the more gruesomely tangible. Truly, the temptation to make mischief increases exponentially with the number of mates around you, the size of the hall in which you’re sitting, and the number of dopey-looking teachers seated up at the front waiting to catch you out.

As such there’s never been a need for anyone to try and dress up or disguise the format of Rule the School with novelties and twists and self-conscious “new series” surprises. Indeed, this first episode was almost identical in structure to the opening of the previous run, right down to the careful sequence of events from the arrival of the “pupils” and their first assembly to the first round of lessons and the post-mortem in the staff room. But again this seemed to be almost tipping a hat to that all-too familiar sense of how going back to school always involved the same grim routines and rituals year after year: back again for a new term, the same old rules, the same old places, and only the faces have changed.

Wisely, perhaps, the production team have resisted casting this series according to antecedent. None of the “teachers” are re-treads of characters or personalities from previous years, and as such each brings something original and unexpected to proceedings. Headmaster Fraser is far more outspoken and impulsive than his immediate predecessor James, as seen by how quickly he ditched the nice guy spiel for that of benevolent dictator when greeted with a choreographed display of rudeness and irresponsibility during the as-ever tumultuous opening assembly. “You’re just making fools of yourself,” he thundered, as his audience tittered and shouted and blithely chewed on great gobs of gum. “This isn’t cool, this is immature. There’s a difference” he continued. Some of the adults had already confided to camera their intention to mess about – one of them boasting proudly of how she was “going to be really really naughty” – but the knowledge that their tomfoolery was pre-meditated actually made them look even more hapless. How could they have forgotten that the most memorable and imaginative forms of misbehaviour are spontaneous, and cooked up in the spur of the moment?

With his students refusing to play by the rules and affecting ever more extreme forms of naughtiness (even answering the invocation “Who rules the school?” with an oblivious “We rule the school!”), the head teacher blew his top. “I can smell mint!” Fraser yelled into the face of Helen, self-appointed ringleader of mayhem. Sent into the corner and ordered to “turn around”, she began rotating a full 360° while doing a stupid dance. The rest of the staff could only sit, mouths agape, appalled.

“It was immature and stupid – no child behaves like they do,” Fraser reflected later. The whole affair set the tone for the rest of the episode, with the teachers approaching their debut lessons voicing stern determination to bring everyone into line and declaring themselves amazed at such exaggerated unruliness. The adults, meanwhile, professed ignorance and insisted they were only acting as they thought real pupils would. This conflict of observation has already made the entire series worthwhile. Does such a gulf of perception exist in real life? Did every single one of the real-life teachers seriously believe they were indulging in an accurate impersonation of the average school kid – or was something more subtle and suggestive underway? Presenter Jake Humphrey stepped in with a timely piece of insight for the adults: “Don’t make the mistake of being childish children when you should be cool kids.” It was an inspired intervention, a world away from the kind of empty platitudes often voiced by hosts of primetime reality-based TV efforts. It also helpfully and succinctly nailed one of the key themes of the show, and nudged the viewer towards the process of forming their own conclusions about what was going on, and why.

When the lessons began, so the focus shifted back on to the rest of the staff. Here again was confirmation that personalities and obsessions new to the series had been carefully selected to offer the both the pupils and the viewer a cunning mix of styles and vocations. Troy briskly led everyone through their first faltering dance steps, and was impressed by their commitment (mirroring her own commitment to turning the show into a personal platform for “showing off my dancing to the public”). The brilliantly moody Hannah had a hell of time attempting to teach “cred”, which found the adults back behind desks and back to no good. “Put all the tables back where they were please,” she pleaded, seconds into the lesson. A few minutes later the humming started (“We all knew that was coming” grinned one of the grown-ups later). “Don’t click your fingers at me, I’m not a dog,” Hannah continued. The entire class was a shambles from start to finish. “They were really proper rude,” was all she could gasp later.

There was just time for an induction into the world of DJing from the tirelessly enthusiastic Jordan. Having finally mastered his uniform, and having struggled gamely through the business of shuffling to Beyonce, Des now had to take his place behind the decks. “Hello, Top of the Pops!” he mugged through the microphone, having the time of his life. Back in the staff room, our exhausted coterie of educators swapped experiences and vowed to work even harder to bring their quarry to heel. Utterly serious about their duties, yet equally determined to enjoy them to the full, it was clear upon whose terms the remaining episodes of Rule the School were to be played. Fraser’s “game” was well and truly afoot. Fittingly, the last words went to the head. “We’ve got an eye on them,” he warned with relish. “We’re onto them.”

Back for a welcome second run, Rule the School continues an impressive sequence of recent CBBC shows that plunge kids into roles and rituals normally patronised by grown-ups – L&K Castaway, DIY TV, Serious Jungle – but which then go one all important step further by coupling those privileges to responsibilities. In this instance, five ordinary children are left almost completely alone to supervise 10 adults, find the right balance between co-operation and coercion, and blend the shameless enjoyment of turning the tables with the rigours of real authority.

This first episode didn’t make clear how both “teachers” and “pupils” were selected for involvement in the show, and instead just dove straight into the first day of term. The participants must have come out of a diligent and thoughtful selection process, however, as they all appeared instantly credible and completely genuine – the kids more so, thanks to being so lucid, on the ball, and just downright witty.

Adam the dance teacher, for instance, set out his stall succinctly: “I think that kids can teach adults quite a few things. We can teach old dogs new tricks.” While the adults testified to how they were looking forward to “learning” from the experience and taking away food for thought, virtually from the off the kids were shown to be of a far more pro-active point of view, thereby precipitating rather than simply stumbling upon the essence of the whole project. It was they who came over as most convincing when discussing what they hoped to get out of the venture. Theo, taking on the brilliant job of “rap teacher”, observed, “We can just give them fun into their lives, which they’ve probably never had,” while Michaela, in charge of drama, emphasised quite rightly, “If they’re willing to co-operate with us, we’re willing to co-operate with them.”

James, the chirpy likeable headmaster, was most adept at expressing clarity of purpose: “I’m a wee bit nervous, but it’s a good challenge.” The test would be “finding a balance between being myself and being a teacher.” It was James who really set the tone for everything that followed thanks to his attitude while getting the adults settled into their dormitories. This was a prospect which one of the “pupils”, Richard, had already rather memorably anticipated as being “exotic, savoury at times”. Matching this for eccentricity was the behaviour of the oldest of the grown-ups, Barbara, who within seconds of making her screen debut bizarrely decided to deface the notice on her dormitory claiming her name was spelt wrong. Witnessing this blatant act James had no compunction in labeling it, “a serious offence – I’ll be talking to the teachers about what to do with you.” When another pupil, Lorna, shuffled in late, claiming she’d not gone to bed early enough, she too was threatened with action at a later date.

Hearing James relate all this to his fellow staff members afterwards it was clear the kids had been able to settle into their roles with ease – and speed. Not obviously playing up to the cameras, the ensemble seemed utterly comfortable with discharging authority and the maxims of their profession – “If you’re willing to learn, I’m willing to teach” – and relished the opportunity provided by the show’s format to stamp their mark on the “pupils” from the outset.

Indeed, James’ initial skirmishes were neatly set up as a prelude to a truly grand event: the first school assembly. This kicked off as it meant to go on when the adults filed in, immediately slumped onto some chairs, only for James to tersely announce, “I haven’t told you to sit!” Earlier on we’d seen Theo declare the staff’s collective intention to “put them in their place straight away.” With the assembly being the first point the entire company were gathered together in one place, there was an excitement in the air as both the viewer and the “pupils” came to terms with what this meant.

There was a slightly combative air to proceedings. When Lorna was asked to stand in preparation for her punishment, James began, “Do you know why you’re standing up, Lorna?” “Because you told me to,” she retorted. James wasn’t having any of this, and went on to dismiss Barbara’s attempt at graffiti with the timeless line, “If you’re gonna do something then don’t do it right in front of my face!” Both offenders were then escorted behind a curtain for their detention: listening to some speed metal music on headphones at full volume. As a footnote to all this the camera then cut to another of the grown-ups, Marlon, in a ludicrously mock-serious interview murmuring how, “The headmaster wanted to assert his authority … the assembly was tense.” His brow furrowed as he insisted, “I need to speak to the headmaster about the punishments, because they seem to be very undercover,” which of course was precisely the point.

Back behind the curtain the two detainees were shown pulling comically awful faces while strapped into their headsets. “How was that?” asked James, briskly, when the ordeal was over. “Excruciating,” they winced. “Good, good,” concluded James. This entire sequence was a wonderful illustration of Rule the School‘s format being exploited to the full, rather than lazily reduced to simple us versus them point scoring. We saw the kids and adults’ respective personalities beginning to come through; a simple but effective exposition on the school “rules”; but above all the sense of everybody of all ages taking pleasure in pushing and exploring the parameters of their new responsibilities.

Later in the programme the adults began their lessons. The best of these turned out to be rap class, helmed by the avuncular Theo. Showing the least amount of nerves of the whole “staff”, he challenged his class to make up a four-line rap about their name, the first step towards fulfilling their main coursework of the term: to become like Eminem. It wasn’t that much of a surprise to find them all up for it. What was really fascinating was how the grown-ups tried to square their task with the urge to retain what they thought was the right sort of dignity. So you had Marlon throwing himself right into it, striking laboured poses as befitting someone who professed to love rap music but wasn’t necessarily that good at performing it. In contrast Nicholas Witchell lookalike Simon was far more intriguing, making up for in energy what he lacked in musicianship. “It’s not the sort of style that I would adopt myself,” he painstakingly explained afterwards, “but I think it fits the music brilliantly. These rappers, they’ve got a message to put across.”

Slightly more conventional was PE, which bore witness to more troublemaking when one of the adults started playing with a basketball before the lesson had begun. “I didn’t say bounce them,” snapped the teacher Susan. “You didn’t say not to,” came the response, prompting Susan to declare, “I will be discussing her behaviour at the next staff meeting!” Then there was the dance class, based around learning a routine from a Justin Timberlake video. Adam was having no nonsense when it came to failing to strike the right moves – “I don’t want to see any of that, because that’s just feeble” – but was so articulate and accomplished in addressing people three times his age he clearly took some of the grown-ups by shock.

It’s that, in the end, which really lifts Rule the School out of the predictable and inevitable. All the featured kids work to earn the viewer’s respect, rather than just expecting you to take their side by default, and struggle to fathom out relationships with their “pupils” that are constructive rather than negative. It’s not just both sides up against each other regardless; James and his staff have their expectations and agenda, and they extend far more than simply giving their erstwhile masters a taste of their own medicine. Thanks to enormously inspired casting and the good sense to play on an audience’s anticipations and need to be surprised, Rule the School delivers the perfect mix of intrigue and irreverence. Same time next week then?