Thousands of pupils are turning skills gained in learning how to scuba dive, fly a plane, stage an ambush and fire a rifle into a qualification worth four GCSEs.
Weapons training, living in "bashes" - makeshift tents - and working out how to dispose of mock toxic waste all feature in a vocational scheme which prepares pupils for careers in the armed and emergency services.
The public services Btec is being taken by Year 11 pupils and sixth-formers in combined cadet forces in 130 British schools - and some are using the result to boost their league table places.
Kingham Hill, the pound;3,702 to pound;6,418-a-term private school which Lord Adonis, the education minister, attended, is asking for its results to be included in overall GCSE passes this year.
Had its 19 Btec passes been included last year, the percentage of pupils getting the equivalent of five A*-C grades at GCSE would have risen from 54 to 69 per cent, taking the school up 17 places in the Oxfordshire league tables.
Martin Morris, headteacher, said: "It did not affect our GCSE scores last year, but this year we will ask for them to be added. It will boost us dramatically.
"We are talking about a bona fide qualification which is a great achievement. It is as valuable as science or maths. It will be of tremendous value for some of the weaker students who were going to struggle to get GCSEs."
Combined cadet forces incorporating sea, air and army cadets operate in 251 schools, of which 53 are state. Just eight of the 130 schools taking the exam offered by Edexcel are state schools - but six have asked for their results to count towards their GCSE scores. The six are Longhill, Brighton; Lordswood boys', Birmingham; Merrill college, Derbyshire; Writhlington and Bath, and Astor college, Dover.
Kingham Hill, where Lord Adonis went on a bursary, and Warminster in Wiltshire are the only two private schools to have asked for the results to be included.
Olivia Bourne, deputy head of Warminster, said it was unlikely to affect the school's GCSE league table position. "All those who got the Btec last year got their five A* to Cs. The year before it could have affected our league table position very slightly as only one boy out of 60 who did the Btec did not get his five passes.
"The course takes a lot of commitment and if you have a pupil who is committed like that the chances are they are going to get their GCSEs anyway."
None of the state schools which have asked for their results to count towards their GCSE score were available for comment.
But Martin Ward, deputy general secretary of the Secondary Heads Association, said state schools were more affected by league tables: "They have to work harder to look good in the league tables. Most independent schools are sufficiently selective to mean they get a 100 per cent A* to C pass rate so there is little point piling on more."
The Cadet Vocational Qualification Office in Surrey has offered the programme for the past three years. Edexcel said 8,000 cadets enrolled this year, 4,500 of them from school CCFs. The rest are sea, air or army cadets in forces outside school. The CVQO said total numbers were likely to rise to 12,000 by September.
Lieutenant Colonel Edward Woods, director of CVQO, said: "Youngsters were leaving school at 16 or 17 and saying they were in the cadets and employers said, 'so what?' Some thought it was a muck-about in green uniforms where they learn to kill people. It is not. Cadets learn team work and leadership. They develop their self-esteem and confidence." l firstname.lastname@example.org
* All about the Btec
* The public service Btec takes between one and two years.
* Cadet training that counts towards it includes weapons training, tactics such as splitting into teams and staging attacks, carrying out first aid on "injured" soldiers, scuba diving, mountaineering, map and compass reading.
* An assignment which includes CV writing, filling in a job application form and doing a mock interview for a military job also contributes towards the qualification.
* It prepares students for careers in the armed forces, fire, police and ambulance services.
* It is equivalent to four GCSE passes.