First and formost, don't expect to become a master of Double Team battles by reading this guide. I will not go over any of my "1337 strategies" here, but this guide is here so you can make your own. This guide will basically list what attacks hurt both opponents or everyone. In addition, I will also list any Abilties that will effect more than one person. Double Team battles are completely different than regular battles. I even have a second team, just for Double Team battles, because there are too many differences from regular matches. I'll stop boring you, let's get to the fun stuff. Oh yea, just to let you know, that some of the DT abilties may be a bit off. There may be a few extra ones not listed and some of these may not effect both foes or everyone. But the attacks are all accurate.
DT Abilities
Arena Trap -
Prevents opponents from escaping. Cloud Nine - Prevents the effect of weather Damp - Prevents anyone from using Explosion or Selfdestruct Drizzle - Brings rain to the field Drought - Brings sunlight to the field Intimidate - Lowers both opponents attack by one level Lightningrod - Any electric attacks go to this Pokemon instead Magnet Pull - Prevents any steel types from switching Minus - Gains 1.5x Special Attack if with Plus Plus - Gains 1.5x Special Attack if with Minus Shadow Tag - Prevents anyone from switching