We tried to pick an even spread across seasons and players, and tried to pick questions we thought at least one person would remember the answer to. We
also wanted questions or answers we thought people would find
entertaining. The seven of us spent several days coming up with nearly
200 questions, then a few more days discussing which ones should make
the cut into the episode, paring them down to the 99 questions that went
into the Quizmaster's arsenal.
Originally our questions were a bit more difficult, but we were asked to tone it down after the snail carnage.
We tried to avoid meta questions about things outside the game, and
stat questions like "how many times did X die of Y cause?"
That said, we also have a second form for the rejected questions, if you want to try your luck with those. :)