To Dispel was to destroy your opponent's Defense on Bakugan Dimensions. To perform this, you have to go into an Advanced Fighting Mode, then hover your cursor over the opponent's Defense. A hammer will then appear over your opponent's Defense. Click on the hammer to dispel your opponent's Defense. It can only be used on your first action. However, there is a glitch that goes along with this; when you attempt to dispel an opponent's Defense, instead of dispelling it, the image of the Defense disappears and the dispel noise is heard on your side until you dispel a Defense successfully. Also, sometimes you will use a dispel and hear the breaking sound, but you will still be able to attack and the opponents defense will still be active.