Follow our guide to ensure you get through your work celebration with your dignity intact.

This coming December, in a tradition that stretches back literally tens of years, men and women from all over the world will don colourful paper hats and gather in their places of work to sing, dance and press unsanitary parts of their bodies against the glass surface of the office photocopier. Yes, that’s right: it’s Christmas party season, that wonderful time of year when the normal rules of business etiquette are temporarily suspended and you’re free to carouse, cavort and flirt the night away with impunity.

Except for just one thing: you aren’t, really, are you? Office parties might be touted as a rare opportunity for employees to let their hair down, but beneath the veneer of festive fun and frivolity lies the uncomfortable truth: that far from being at liberty to do whatever you want, you are in fact operating under the watchful gaze of upper management, and as such are only ever one ill-advised dance move away from landing yourself in an employment tribunal. So, while it’s important that you have a good time – what else, after all, is a party for? – it’s vital that you remember where to draw the line.

Here, we outline a few rules to follow and pitfalls to sidestep. If you plan on emerging from this annual ordeal with your professional reputation – not to mention your dignity – intact, then you owe it to yourself to read on. If you’re too busy to do so, the entire article can be roughly summed up in the following five words: please, don’t be that guy.

Outside of a work environment, the words “free” and “bar” are among the sweetest in the English language, conveying as they do images of Dionysian revelries on lush, Arcadian pastures. But office parties do not take place outside of a work environment. In fact, they quite often take place in the actual office, which is about as “work environment” as it’s possible to get. And against this backdrop, a free bar presents a rather more dangerous proposition.

As anybody familiar with the words “wine o’ clock” will know, alcohol has miraculous powers when consumed in small to moderate amounts: it conceals anxiety, elicits feelings of euphoria and gives even mind-numbingly tedious people – plenty of whom you’re likely to meet at the office Christmas party, by the way – the illusion of being entertaining. In larger quantities? Let’s just say that if you grease the wheels too much, they’re in real danger of falling off.

Every embarrassing office party cliché in the book – the refashioning of neckties into Karate Kid-style headbands; the soulful, if atonal, renditions of 1980s power ballads, delivered, à la Bridget Jones, from the top of the boardroom table; the ill-advised clinches in the stationery cupboard with somebody called Karen or Deborah from accounts (why do they always work in accounts?) – owes its very existence to alcohol. If you don’t want to be “that guy”, then please: eat before you arrive, consume in moderation.

It can be tempting – especially when buoyed up by Dutch courage after a couple of hours abusing the free bar – to utilise the office party as an opportunity to launch a charm offensive on your longstanding office crush. Before you jump in with both feet, though, it’s worth asking yourself the following series of questions. One: is there any reason to believe that the person I am interested in has any interest in me? Two: have we ever actually spoken before? Three: come to think of it, does he/she even know who I am? If the answer to any of these questions is no, then you have clearly not completed the necessary groundwork, and should consider postponing your declaration of undying love for another time. (If it really is undying, then you’ll be in no particular rush.)

A little innocent flirting is absolutely fine, assuming of course that it takes place between mutual parties. When it arrives unbidden, however, it’s far more likely come across as creepy than cute. We are reminded as we write this of one employee who decided, for reasons mysterious to all but him, to suspend a bunch of mistletoe in front of his face by means of a specially constructed headband. He moved (was asked to move) to an off-site location shortly after the New Year and has not been heard from since.

One final, and very important, point on office romance: whatever you do, keep your damned paws to yourself. At best, you’ll get stuck with an unfortunate sobriquet like “Handsy Chris” that follows you around for the rest of your career. At worst, you’ll wake up the morning after to an accusation of indecent assault. Speaking of the morning after…

Thanks to a crowded festive schedule and a tendency among senior management to defer booking a venue until the last possible minute, you can expect your office Christmas party not to take place on a Friday, which would obviously make a lot of sense, but slap-bang in the middle of the working week instead. Use this unfortunate piece of scheduling to your advantage by reminding yourself at regular intervals throughout the evening that you are required to be at your desk the next morning. Write it on a post-it note and stick it to your credit card. Say the words out loud – “I need to be at my desk tomorrow morning” – as you return to the bar for yet another Advocaat on the rocks because they ran out of beer, spirits and wine an hour ago. And don’t let the hour get too late: wear a watch, and make sure that you look at it. (Not while you’re mid-conversation with the boss, mind.)

The office party is many things: a team-building activity; a networking opportunity; a chance for you to let off steam after a long year of hard work. What it is not is an excuse to crawl into the office the next day an hour late and reeking of booze. If you’re feeling the worse for wear, then drop an Alka-Seltzer or two and put a brave face on it. Your colleagues will no doubt be sympathetic to your plight; most of them will be in the same boat, after all.