I noticed in the Star Trek movie, 2009, that when Kirk and Spock boarded the Romulan ship, they had their phasers set on "kill", which struck me as odd, since Star Trek characters usually fire on "stun". Suddenly, I realized that we almost never saw a Vulcan or Romulan stunned in TV Trek. Is it possible that the stun doesn't work well on Vulcans and Romulans? Makes me wonder: 1) How long does a stun last? Was it effective in knocking out an enemy for hours? If then, I would think they would rely on stun in most situations... 2)Why, on DS9, did they often seem to fire their phasers on the lethal setting (e.g. against the Klingons in "Way of the Warrior"; against the Jem'Hadar whenever they encountered them) and blow up enemy ships, yet in TNG, they established that Starfleet officers almost always fire to stun, and to disable, rather than destroy, other hostile vessels. The situations often seemed similar, so I didn't understand where they would make the decision to use one option over the other? One thing I always liked about Star Trek was that it was one of the only shows I watched as a kid where the heroes fired nonlethal weapons, so the enemies could recover once the conflict was over - I liked that, compared to other sci-fi shows.