You may challenge only the character one rank above your own, and you can also only challenge one person every five days real life time. To challenge another, you post in the correct race sticky stating that you wish to fight for their spot. Then, you pm said person stating your challenge, and make a topic in the postion battles area. If the person does not respond within 48 hours and does not have a vaild absence topic, then you win by default and the spot is yours. No, I have to go to the store or something like that is not a vaild absence. Also, these battles take place in character, do remember that.