Fly is a Flying type damage-dealing move.
During the semi-invulnerable turn, the user will avoid all attacks targetting it. Exceptions are the moves Gust, Twister, Thunder, Hurricane and Sky Uppercut, which will still successfully hit. Gust and Twister will also cause double damage if hit during Fly's semi-invulnerable turn. Furthermore, if any of the two Pokémons have the ability No Guard, any attack will successfully hit.
If the user is holding a Power Herb, it will consume the Power Herb and immediately attack on the first turn without going into the semi-invulnerable turn.
- Two-turn charge moves such as Solar Beam will fail to charge if used during the opponent's semi-invulnerable turn of Fly. (Report thread)
- NPC Trainers will choose a random move during the player's semi-invulnerable turn, even if their attack would be executed after the player's Pokémon. They will however always select moves that can hit during Fly's semi-invulnerable turn if they known one of them.
- Smack Down does not hit during Fly's semi-invulnerable turn, as it is not coded.
- Jump Kick and High Jump Kick users take no crash damage when used during Fly's semi-invulnerable turn. (Report thread)
Out of Battle
Unlike in the official games, Fly has no functionality outside of battle. Quick movement between cities is instead done by the use of various Transports.