Now, it seems we may lose the other half of the creative force behind the great-grandfather of role-playing games. Dave Arneson, D&D's co-creator, has battled cancer for many years. It seems that his cancer has unexpectedly worsened just this week, to the point that he is in the hospital. He is heavily sedated and not doing well. He is not expected to live for more than a couple days, if that long.