These are the different types of Dragonballs and what they can do. To find the Dragonballs post a message saying that you are looking for them. When you have found them, the "creator" of those balls will send you an e-mail telling yo to post your wish(es). You must be on that planet to get it's Dragonballs. Any number of people can look for the Dragonballs, but You can't just find 1 Dragonball and then leave to find a set on another planet. You must find the set or what is left of them. And if you and another person start looking on the same day as you, then both of you will find 3 of the Dragonballs. At this point you and the other person will have a fight to see who gets the final dragonball....but then the person who wins also gets the 3 dragonballs his opponent had. If 3 people look for the dargonballs then each person ends with 2 and the 2 more evenly matched will fight and gain possesion off the other's dragonballs, but the 3rd person will find the last dragonball. The 3rd person and the victor can fight, but they don't have to.
Earth Dragonballs (one wish)
Namek/ New Namek Dragonballs (three wishes)
Darkstar Balls
