The football simulation is startling in its realism. The "camera" swoops through the stadium; the players perform tricks with abandon. The stadium is rendered with startling clarity. And on the sound-track the commentator scatters pearls of wisdom.

A goal flies in. "The shooter let his happiness burst!" he yells. "You'd think he had a sea urchin in his shorts!"

No, it's not Harry Hill on the mike. This is simply how Ocean Software's forthcoming Uefa Soccer computer game would sound if the publisher didn't bother to amend the script submitted by its French-speaking developers. Ocean will, of course, rewrite the commentary. But this raw example illustrates how ludicrous software can be when localisation is not taken seriously. It sounds silly. Worse, it won't make money.

Today, software localisation is big business. And, needless to say, it has taken commerce rather than the love between nations to make the trade realise it. Now that software development costs can go up to pounds 2m, it would be commercial suicide to ignore the huge number of overseas gamers.

"The European market should represent 40 per cent of any decent global publisher's revenue," says Bob Dewar, managing director of Activision Europe. "The machines are there; why not the sales?"

How different from the late Eighties and early Nineties, when localisation was an afterthought often carried out by local language agencies, or even friends. One giant US publisher used an Austrian to translate and record the sound-track for the German version of a game - the equivalent of recording an English-language title with a Welsh accent. No disrespect to the Welsh, but it is a bizarre thought.

Specialist agencies such as SDL, ELG and Polylang agree that publishers now recognise the need for proper localisation. But the greatest battle is getting them adopt working practices that make translation easier.

Some companies are already meticulous in their planning. When Attica, a small multimedia publisher, was recording roadside scenes for a first- aid CD to be released later this year, it filmed only in one-way streets to avoid the problem of showing drivers on the left or right. Meanwhile, Maxis is considering whether to depict all road signs for Sim City 3000 not only in the language of individual countries, but also in their local typeface and design style.

Sometimes there are factors that only a localisation specialist may be aware of. Take speech bubbles. Here, the agencies say, it is important to leave plenty of space; foreign words are often longer than the English ones. The German for "bus stop", for example, is strassenbahnhaltestelle.

Ideally a publisher should contact a localisation specialist right at the start of a product's life, to discuss marketing issues such as the target audience, as well as technical considerations. The timing for the handover of software code is crucial. If done too late, a simultaneous release across all territories - so important for marketing - is impossible. If done too early, there's the risk of costly amendments later.

Lotte Andersen, general manager of Polylang, explains: "We had a client who told us they wanted one line in the script changed. For us that meant rehiring the actor and rebooking the studio. It took days, and took us over budget."

Clearly, localisation agencies depend as much on programming skills as on their ability with languages. SDL, for example, is home to pounds 750,000- worth of kit. According to Mark Lancaster, SDL's managing director, linguistics is only one-third of what the company does. The rest is split equally between technical work and project management.

Although they have different methods, all the agencies try to carry out or monitor translations in the country the localisation is aimed at. SDL has 50 translators in the UK and 500 outside. And they're all encouraged to stay in touch with their home country's culture. In fact, Polylang's UK-based language staff are supplied with free satellite dishes so they can watch their "own" TV.

They need the rest. The advent of CD-Rom has hugely expanded the content of games and multimedia titles. On average, one translator produces up to 3,000 words a day. With three working on a single project, that's 45,000 words a week.

Obviously, localisation will be ever more important. But despite this, all the agencies spoken to admitted that many clients still find it difficult to plan adequately.

It's costing them dear. Andersen tells a typical story: "We saw a review in a German magazine which gave a localised product just 18 per cent, and we thought, `we've got to see this'. But we couldn't find it anywhere. No one stocked it"n

Tim Green