Arguably considered to be a British Army joke whenever they face an enemy of supposedly amateur reputation - but I'm not saying other countries don't use it or even invented it. The opponents (Dutch, Italians, etc) and specific batallion (Paras, SAS, SBS, RM) are always changing. At the moment it is currently being used "against" the Taliban with the Royal Marines - thus reflecting the immediate situation, it goes as follows.
Somewhere is deepest, darkest Afghanistan, Mullah Omar and Osama Bin Laden are skulking about on a mountain with hundreds of their evil henchmen and soliders.
Suddenly from behind a small ditch, an unknown voice shouts :
"One British Royal Marine is worth a 100 Taliban!!!"
The two evil leaders are infuriated, and Osama Bin Laden sends a few dozen of his best henchmen to dispatch the infidel. "Go kill that idiot. And bring his head back on a stick"
The henchmen walk over the ditch, and much automatic gunfire, explosions and bloody slaughter is heard. Five minutes of silence pass, and then the same cocky voice is heard :
"Ha! Didn't you hear me mate?! I said ONE British Royal Marine is worth a HUNDRED Taliban!!!"
Osama is embarassed, and Mullah Omar has lost his patience, instructing his men to rip the infidel to pieces. The One-eyed Mad Mullah gets 200 of his cracktroops and leads them storming over the ditch, spraying hails of gunfire and mortars over it as they advance.
A WWIII type battle ensues, blood, guts and limbs go flying, and for Osama trying to work it all out (but the view being obscured by the ditch) the result seems uncertain. It goes deathly quiet, with just the sound of heavy breathing. Then in the shadows, the solitary figure crawls towards Mr Bin Laden in a manner suggesting a very fatal wounding.
Osama rushes forwards, and shakes the dying Mullah Omar. "What happened? What happened?!?!?!"
With his last breath he explains....
"It was a perfidious infidel trick Osama....
- There were... TWO of them!!!!"
and quickly expires, departing to meet Allah (some chance!).