From the author's site:
Like an growing number of roleplayers over the last two decades I have found the increasing complexity and length of most commercial roleplaying systems overwhelming. I’m sorry everyone, but I like to play RPG’s for fun, not as a second life. I like to be carried along by the story, not the dice. I like to spend my playing time finding creative solutions to seemingly intractable problems, not rolling handfuls of dice against skill tables to see if I succeed. (...)
Already known for my ability to distill a wargame down to a single page (FUBAR) I decided to try and do the same with a classic fantasy RPG. Well folks I failed.. well not entirely. Dead Simple is indeed a single page, but I couldn’t help myself and wrote a dozen supplements on such things as creating dungeons, villages, cities and monsters, each a single page long.
So the rules now span a dozen pages, but you still only need the first page to play a game. You can create and develop a character and play it in a game with that single page.