Bang! I'm woken up from a deep sleep in the middle of my first night at Witcher School by the sound of explosions in the castle courtyard below. Witcher masters yell as they stamp up the stairs and open the heavy wooden doors to our dormitory tower to wake us. I find my uniform - rough tanned trousers and shirt, padded brown gambeson fastened over the top - and throw it on. It is freezing.

There is absolute chaos below. The princess, brought here in chains by a posse of Temerian soldiers, has turned into a werewolf and escaped. We all feared it might happen. A soldier writhes in agony on the floor; a guard sits dazed and confused by the door; and a trail of blood leads to the castle walls and beyond, out into the bitingly cold and black night. That's where we're headed, unarmed, to get the princess back.

This content is hosted on an external platform, which will only display it if you accept targeting cookies. Please enable cookies to view. Manage cookie settings

We move out in a line guided by witcher masters and their fiery torches, nervously edging forwards. Then, a savage roar and scream, and torchlight streaming towards the source. It's the princess - no longer the harmless young lady chained to a cold laboratory floor but a large, snarling monster, chest heaving for air. Grandmaster Swar steps forward and unsheathes his sword.

The werewolf retreats - and a trap is sprung. Master Dirk leads a group of adepts in casting the magical Igni Sign and flames flare in a circle around the monster. Dirk approaches from the side, mace in hand, and stuns with the Axii Sign before leaping to strike. Subdued, reeling, the werewolf is led by the mob back to the castle, the casualties of her escape carried behind. The man attacked in the woods was from our group. He doesn't make it back alive.

I'm at Witcher School, all the way over in wintry Poland, living in a centuries-old hilltop castle for the weekend. We have the complete run of the place: we sleep here, take witcher lessons here, eat here and fight monsters here. We are learning to become witchers. All signs of modern life have been disguised or hidden, electronics outlawed (except in dormitories). For the duration the castle will be lit by torches and candles and by fires roaring in hearths. And everyone here - everyone - is in costume.

Witcher School is a weekend-long live action role-play event - or, if you will, a larp. Imagine a video game, come to life. The event ran for the first time last year, though was only open to locals; this year it's international, and is carried out entirely in English. People have come as far as from America to play, as well as from all over Europe, and for many (myself included) this is their first larp. It's all a testament to the extraordinary success of The Witcher video games, which have propelled Andrzej Sapkowski's fiction far beyond Poland. CD Projekt has nothing to do with the Witcher School, incidentally, beyond being name-checked as a partner.

Zamek Grodziec, the gorgeous backdrop for the school.

Witcher School costs €350 (£276) to attend, a price that includes a weekend's accommodation, food and rental of a costume, although travel's not included. It's a significant amount - as much as week's break somewhere hot - but it's a far bigger and more impressive operation than I expected. There are 39 of us playing and as many again of them organising and taking on various roles. The organisers work tirelessly all weekend on a number of memorable events.

How you play the game is explained in a series of workshops upon arrival, and there are so many new players this explanation is essential. It's not complicated; the general rule of thumb is 'don't be an asshole'. If you're hit, act hit. Support the role-play, don't poo-poo it because you want to be the hero. Do what's good for the game. There are more specific mechanics, including sex cards non-player characters can hand out to simulate the raunchy side of the Witcher games and fiction without things getting weird. There are safe words, and there are some guidelines about how often adepts like us can use witcher magic - i.e. we can't, really. Not yet.

Then, after the workshops and dinner, the game begins, and runs non-stop Thursday evening to Saturday night. Dormitories may be flagged as 'out of game', and the organiser's backstage area and office is 'out of game', but otherwise everywhere and everyone will be in character for the duration. I'm Lester, an email I receive a few days before the event tells me, a spy and a deserter from the Temerian army captured and forced to infiltrate Witcher School. Will I find the Temerian Captain and keep them happy with information, or will I be discovered by the witchers and punished? Armed with motivations and backstory I stride into the courtyard with the other recruits and stand before the witcher masters, bedecked in their impressive assortments of leather and metal, capes and scars. The game begins.

Witcher School isn't for the faint-hearted; it's more like military boot camp than a holiday. We are pushed to physical breaking point - some do break, almost literally - and robbed of sleep. And Poland in March is bitterly cold beyond those deceptively blue skies.

There are two full days. Friday starts after a broken night's sleep chasing a werewolf, as one does in these parts, followed up by exercise around the castle grounds at 7am. We run, we jump, we stretch and we do the first of what must be hundreds of push-ups over the course of the weekend. After breakfast we launch into our lessons.

The team at Witcher School do an amazing job of conjuring up a real spectacle.

First there's leatherworking, where we cut circles in a cow's hide and sew it into pouches to use during the event. Then there's alchemy in a cellar where we grind and boil and measure and stir, concocting essential potions for the night ahead. We make Swallow to heal, Cat to see in the dark and Golden Oriole to neutralise poisons.

After, it's archery to shoot at targets and each other in an exhausting game of capture the knife. Then we're onto swordfighting to learn basics of attack and defence over and over again. By the end of the afternoon we're a sweaty and bruised heap but the day is far from over. That evening we face the first of our witcher trials - and their severity has not been underplayed.

My group of five waits until nearly midnight for our turn, before walking into the pitch black woods to face our first challenge: destroy a ghouls' nest. In the dark the first thing you notice is their snarling, then their silhouette, and you don't notice the ghouls at your flank and rear until it's too late and the melee has begun. They don't go down easily and they swing wildly, one so fiercely it sent me one way and my glasses another, and I landed with a thud on the frozen mud. With the help of Swallow healing potions we survive, but our stores are badly depleted.

We suffer no such maulings when stealing magical stones from a demon, but running around in the dark has its own perils, and we tumble and crash into the hazardous night.

But our final challenge is the big one. We must climb to the cursed upper level of the castle and battle the wraiths waiting there, so we take our Cat potions and shuffle down creepy corridors towards them. They're serene at first, like spectral patients in an asylum, then all hell breaks loose. They fly at us with weapons, thrashing mercilessly - this isn't the regimented fencing we'd practiced earlier in the day. We're clobbered, hammered from head to toe, and it takes an intervention from our supervising master witcher to drive them back. We press onto the final room where a male wraith ferociously protects a mother and her child. We aren't prepared for this. But we were instructed to kill without hesitation so into the cot my sword thuds, and the crying and the trial are over. Grandmaster Swar is proud.

Alongside our witcher training an overarching storyline has been unfolding, and the main characters make themselves available to you as much as possible. They visit lessons, they wander the castle grounds, and they eat alongside you. They may even single you out. And they're open and approachable to you and your stories.

Eventually I make contact with my handler the Temerian Captain, and she asks me to steal a diary from Grandmaster Swar's room. That's proper naughty but I decide to try, sneaking in and rummaging around only to discover someone has beaten me to it. So I throw in my lot with the witchers, confessing I'm a spy to Swar - leaving out the bit about rummaging around his room. He says he'll protect me and confesses a murderous secret in return. All of a sudden I'm speaking for him in a crucial scene at the climax of the story. Without wanting to spoil if for you should you ever go yourself, it escalates. Quickly. And that's just my story - all 38 other players are just as busy working on their own.

It's not all play and pleasure.

Yet although the role-playing efforts of the cast are herculean, all the characters improvise in a second language, and it can't help but have an effect. It slows interactions, draws things out. Key scenes lack the kind of verve and variety an acting troupe would throw at them and dip in energy and entertainment as a result. There are only so many angry tirades one can watch. Nevertheless, the commitment is wonderful; overhearing in-character conversations between witcher masters as they walk apparently unnoticed across the castle courtyard is hair-tinglingly cool.

None of it would work without our willing participation, of course, and our own role-play. It's not a one-way street. We aren't really fighting monsters or casting magic or hitting each other with metal swords but pretending to - although there's nothing pretend about the welts and bruises the latex weapons and foam-tipped arrows leave. But it's not all make-believe; wherever possible Witcher School employs theatrical tricks to lend an immersive helping hand. It may be an ultraviolet light to simulate being able to see in the dark; or a pyrotechnic display to simulate a fire spell; or a very convincing monster crew twisting and contorting into believable-enough replicas of the fantasy thing. It sounds silly but it works, it really does, and to the man who wore a wetsuit in the icy night so he could emerge as a drowner from a pond, over and over again: you are my hero.

Nevertheless, as tiredness and coldness crept in so did cracks in my willing participation, and in those moments I cringed and I scrutinised the cold, hard workings of a game around me. But something always won me back, and for every cringe there was a 'wow', when the elements aligned to great effect and the illusion held splendidly. It all works is because of the place Witcher School comes from: the heart. This isn't a Disneyland ride created to flawlessly and mechanically play to hordes of visitors over and over again, but a living, breathing event shaped by the people playing it - players, non-player characters and organisers alike. These witcher masters and princesses and sorceresses aren't actors here for paychecks (their board is covered) but larpers here to play with us, our reaction their reward, and it's the authenticity of their passion that permeates everything and wins out.

When we leave on Sunday morning, resembling the walking dead, it isn't just to the fantasy of being witchers graduating Witcher School that we belong, but to the community of this larp. The camaraderie of overcoming extraordinary challenges in extraordinary circumstances is potent, and on all the wearied faces are smiles and fond farewells. These people who sat in an airport as strangers roughly 48 hours before are now friends smiling at shared memories, so many shared memories. Witcher School won't be everyone's cup of tea and it doesn't come cheap, but for those who are interested it is, simply, unforgettable.

This content is hosted on an external platform, which will only display it if you accept targeting cookies. Please enable cookies to view. Manage cookie settings This is the official video of the event.