The term "the magic circle" is used informally to describe the top commercial law firms in the UK, all based in and around the City of London. Here we introduce them, explain what they have in common, and how they're different.

What distinguishes these firms from the rest of the market is the amount of money they make. Profit per equity partner for magic circle firms, the preferred way of measuring how profitable law firms are based on how much their top partners earn, which is typically in excess of £1 million a year.

Most of these firms are also very large, with offices spread across the globe.

Who makes up the magic circle?

It's a very exclusive club, with only five members: Allen & Overy, Clifford Chance, Freshfields Bruckhaus Deringer, Linklaters, and Slaughter and May.

The list of firms regarded as being part of this club hasn't changed over the past couple of decades and they're fiercely competitive.

Why work for them?

If you're lucky enough to secure a training contract with a magic circle firm then you can expect to work with some of the biggest and best-known corporations, banks and governments.

A graduate role here might well be better paid and more international than one at many other UK firms, but your tasks will be challenging and the hours can be incredibly long.

Allen & Overy

Headquarters

1 Bishops Square, London

Best known for

Finance

A&O is known for having the best finance practice in the City and their client list includes bulge bracket banks such as Goldman Sachs, J.P. Morgan and Barclays.

However Allen & Overy first made a name for itself after partner George Allen took up the role of adviser to Edward VIII during the abdication crisis in 1936.

Now A&O has a more international focus; 60 per cent of its revenue comes from work outside the UK. In addition, nearly 70 per cent of their work involves two or more legal jurisdictions.

Allen & Overy is also rumoured to be the nicest and the most laid-back of the magic circle firms. It's been said that A&O is a little less bothered about what university its trainees went to than some of the others in the magic circle.

Clifford Chance

Headquarters

10 Upper Bank Street, London

Best known for

Finance

CC is one of the big hitters both in the UK and abroad, and has the highest turnover of any of the magic circle firms thanks to many billion-pound international finance deals.

It's also one of the youngest firms in the group and is supposedly percieved by the more snobbish members of the magic circle as slightly more "common".

This hasn't been helped by the fact that its lawyers have in the past attracted unwanted press attention after enjoying an alcoholic beverage or three.

However, Clifford Chance is often viewed as one of the more innovative and entrepreneurial magic circle firms. For instance, two years ago the firm opened an office in Seoul, South Korea - the first of the magic circle to do so.

Freshfields

Headquarters

65 Fleet Street, London

Best known for

Corporate

When it comes to prestige, you probably can't do better than a firm that can trace its history back to 1743. Its first client was the Bank of England and it also acted as official legal services provider to the London 2012 Olympic and Paralympic Games.

Its supremacy and rumoured penchant for attractive, sporty Oxbridge types has previously earned it the moniker the "blues and blondes" firm.

The firm also has strong German links following a three-way merger with two German firms in 2000, which led to its current incarnation as Freshfields Bruckhaus Deringer.

It seems to have got its strategy right as it's profit per equity partner is growing and has it has re-opened its Singapore office.

Linklaters

Headquarters

1 Silk Street, London

Best known for

Corporate, finance

Like the annoying kid who got all A* in their GCSEs, Linklaters is the ambitious (and maybe slightly aggressive) all-rounder of the magic circle with an impressive client list to match.

It has a strong finance practice, and on the corporate side is only second to Slaughter and May in terms of the number of FTSE 100 clients it acts for.

Its lawyers have recently advised News Corporation's Independent Management and Standards Committee following the phone hacking scandal.

The firm has a fierce rivalry with Freshfields, and recently replaced it as advisor to Lloyds Bank over the mis-selling of payment protection insurance (PPI). However it still trails behind Freshfields when it comes to turnover and profit per equity partner.

Slaughter and May

Headquarters

1 Bunhill Row, London

Best known for

Corporate

Slaughters is the smallest of all the magic circle firms, yet has the most FTSE 100 clients on its books.

It's also the most prestigious and profitable of the group, and the most decorated with awards. Unlike its rivals, who operate numerous offices abroad, Slaughters prefers to outsource its international work, relying on what are known as "best friend" relationships with top local firms.

The firm has been seen as overly formal and as obsessed with excellence and perfection, and has been accused of hiring mainly a preppy, Oxbridge-educated elite.

However it also reports some of the best retention rates out of all magic circle firms, suggesting a strong level of loyalty to Slaughters and a genuine collegiate atmosphere.

And finally...

Many still view magic circle firms as employing the best lawyers in the UK, who do the most prestigious work and enjoy the best rewards.

But for some, the magic circle is not as magic as it first seems. There are plenty of other top City firms with equivalent expertise, especially in areas other than finance and corporate law. US firms are also worth noting - many are snapping up smaller UK firms and will pay more for your time than magic circle firms do.

Also, clients' increasingly tight legal budgets are creating interesting opportunities at less prestigious and cheaper law firms and even at the legal arms of professional services firms.