Dungeons and Data Science, or D&D.Sci, is a series of analytical exercises played on Less Wrong, framed as problems in a D&D style adventuring world.
Generally D&D.Sci exercises will give the player a set of data but not the rules used to generate it, and the player must extrapolate patterns from the data in order to optimize the solution to some problem. After each exercise there is usually a follow-up post which explains the underlying rules of the scenario and gives a score to each player who participated at the time.