[Important Update: According to a message I just received from Dave's family, he's still alive but was moved to a hospice. See Dave Arneson Makes Save vs Death for more info.]
I just opened my email to some sad, but not unexpected, news. Dave Arneson has lost his battle with cancer. He died at age 61. I don't have a lot more information at the moment. Dave had been battling cancer for some time but things seemed to be looking pretty good. Then he took a sudden turn for the worse in the last week.
In some ways, Dave was more important to my personal gaming than Gary was. Temple of the Frog in the original Blackmoor supplement was the first dungeon I ever saw designed by someone who was familiar with the way D&D was supposed to be played. First Fantasy Campaign from Judges Guild was the first chance I had to see how a full blown campaign was set up and ran by one of the original designers. Gary may have provided most of the rules we used and Judges Guild the Wilderness setting and City-State we played in, but Dave provided the first examples of a complete dungeon and a complete campaign that I had. He provided the spark that became the soul of my campaigns.
Thanks again, Dave. I say "again" because Dave, like Gary, remained accessible to those playing the games they created until the end. I got to tell both Gary and Dave directly how much what they did way back in the early 1970s did for me.