If you are referring to the children's game of "Rock, Paper, Scisors" as the article refers to, I have never heard of it referred to as Roshambo.
In the US, school children always refer to it as "Rock, Paper, Scisors", the same way that you refer to it as <Schere, Stein, Papier>
Roshambo might be a UK colloquialism, but I have never heard it used in the US. In fact, the only thing close to that, that I am aware of is something totally different - the French general Jean Baptiste Donatien de Vimeur, Comte de. Rochambeau was the commander of the French forces during the American Revolution, and was the commanding general at the Battle of Yorktown.