I did not know that! I never want to buy the dungeons key because I don't think I can play it. Barely survive in normal campaign ..LOL But I finished it, with a lot of deaths. I will try this explorer, If I can solo it, I may buy the keys. I don't like the game that has timer and equipment lock. What is the point to rush the player and restrain to change gear while we have millions guns?? Good company motto is, "We make product that customer like". Bungie should motto should be "We make game that customers like to play" not "We make game that we like to play". I will never buy any product that I can't use. Never buy game that I can't play or not fun to play. Playing video game is for entertainment not work or job or a bragging tool.