The athlete's time will be electronically determined by a chip given to the athlete prior to the race. Instructions will be given, but it is your responsibility to make sure the chip is properly affixed.
Athletes are encouraged to race intelligently. There are several points in the course in which attempting to pass another athlete is ill-advised. Dave Castro covers this and more as he ran the entire course mic'd, talking about the terrain and recommended strategies. It is strongly recommended that all individual competitors watch this HOUR LONG video on the event.
Proper footwear (off-trail running shoes with decent knobs) is encouraged. Leg protection may also be desired (gaiters or Skins Sox).
Even watching the video and considering the route, it is very easy to underestimate the potency of the terrain. This event, which is just the first of five on Saturday and eight for the weekend, is still very much unknown. And, unlike many (all?) other competitions, this run is followed in short order by the second event, which will be a heavy lift in a timed environment (full details announced Friday morning).