American boys who swot up on The Dangerous Book for Boys, a runaway British bestseller, will learn nothing about such staples of British childhood as conkers and cricket.

The book has been extensively rewritten for the American market to replace conkers with “stickball” and the laws of cricket with the equally incomprehensible Navajo Code Talkers’ Dictionary.

A lesson on the etymology of “cor blimey” has been dropped, and a trick involving hiding a £1 coin behind your ear now uses an American quarter.

A section listing the kings and queens of England and Scotland has been replaced with the “most valuable players” in baseball.

Egbert, the first king of Wessex from 802 to 839, is thus usurped by Lefty Grove, of Philadelphia, who won the baseball honour in 1931.

The rewritten US edition suggests that despite globalisation, the two peoples remain divided by their common language.

A warning that life without girls would be “one long rugby locker room” is changed to “one long football locker room” – presumably American football. The “taw” in a game of marbles has been translated as “shooter”.

The publisher, Harper Collins, a sister company to The Times, initially ordered 91,000 copies of the popular primer on British boyhood by the brothers Conn and Hal Iggulden for the American market but has had to increase that to more than 400,000.

“We added some things,” Conn Iggulden said on the Today show on NBC. “There’s a section on famous battles, and we had to add in Gettysburg and the Alamo, and a few things like the Gettysburg Address. We took out the section on the British Empire, because it didn’t have so much resonance here. And we put in things like American states and American mountains, and a few things like that. British trees are not so fascinating to Americans.”

Matthew Benjamin, the book’s US editor, said that about 30 per cent of the US edition was new material suggested by the publishers after a powwow among American males in the office.

“What is interesting about the book and what makes it contagious is Conn and Hal’s voice. We didn’t want to wreck that,” he said.

“Basically, we made recommendations to them and they created the pieces. Everything we suggested they totally loved.

Conn’s background is historical fiction and he loved the historical battles. He loved learning about them. He was just entrapped by the information.” The book, which has reached No 3 on the Wall Street Journal’s nonfiction bestseller list, appears to be driven partly by American fascination with British schoolboys created by the Harry Potter books.

“I feel like Harry Potter has become part of our lexicon,” Mr Benjamin said. “I would hesitate to say that American boys want to grow up to be British kids, but it’s part of their fantasy.”

They will not grow up dreaming of being Horatio Nelson. The admiral’s death at Trafalgar has been replaced in the Extraordinary Stories section by the Wright Brothers’ first powered flight.

There is no list of Britain’s patron saints nor any of the maps of the changing Britain from Roman times to the Norman Conquest.

The British schoolboy classic 1066 and All That has been dropped from the list of must-read books and an entire ten-page section on the British Empire, describing “five centuries of energy, triumph, disaster, heroism and invention”, has been jettisoned.

Instead, American boys get added lessons about the Revolutionary War battles of Lexington and Concord, a list of the 50 states and a complete text of the Declaration of Independence.

The rules of “soccer” are included because of its increasingly popularity in American schools. Strangely, rugby also survives the transatlantic translation, whereas cricket does not.

“Cricket is just not an experience for American boys, but American boys do experience rugby and they probably want to know more about it because it’s so rough, slamming people around,” Mr Benjamin said.

Elixir of youth

— The book was written by Conn and Hal Iggueldon

— It won Book of the Year at 2007 British Book Awards

— The authors say: “The one thing that we always say about childhood is that we seemed to have more time back then. This book will help you recapture those Sunday afternoons and long summers – because they’re still long if you know how to look at them”

Sources: dangerousbookforboys.com; www.britishbookawards.co.uk

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