From Bulbapedia, the community-driven Pokémon encyclopedia.
Revision as of 15:48, 29 June 2017 by Pumpkinking0192(talk | contribs)(→Effect: Technically the important part is that it bursts before the *check*. The literal words of what you wrote are fairly obvious: that the holder is affected by terrain after the burst.)
The Air Balloon makes the holder ungrounded, which means that the holder is immune to damaging Ground-type moves and several related effects. If the holder or its substitute is hit by a damaging move, the Air Balloon is destroyed. A message is displayed when a Pokémon is sent into battle while holding an Air Balloon (if its effect is not negated).
The Air Balloon does not make the holder ungrounded while Gravity is in effect or if it is under the effect of Ingrain, Smack Down or Thousand Arrows (but this does not prevent it from bursting).
An Air Balloon will not burst while Magic Room is in effect, or if the holder has the Ability Klutz or is under the effect of Embargo. A burst Air Balloon cannot be recovered with Recycle or Pickup. The Air Balloon bursts before it can be stolen by Thief, Covet, or Magician and before the game checks whether the holder is affected by terrain.