Complex sentence: The earliest known video game competition took place on October 19,1972 at Stanford University, for the game "Spacewar", where students were invited to an "Intergalactic spacewar olympics" whose grand prize was a year's subscription for "Rolling Stone".
Split into simpler sentences: The earliest known video game competition took place on October 19,1972 at Stanford University for the game "Spacewar". Stanford students were invited to an "Intergalactic spacewar olympics" whose grand prize was a year's subscription for "Rolling Stone".