The Iron Ball (Japanese: くろいてっきゅう Black Iron Ball) is a type of held item introduced in Generation IV. It grounds the holder and lowers their Speed.
The Iron Ball halves the holder's Speed and makes it grounded. Due to being grounded, it becomes susceptible to Ground-type moves, Arena Trap, the entry hazards Spikes, Toxic Spikes and Sticky Web, and terrain, even if it is Flying-type, has the Ability Levitate, or under the effect of Telekinesis and Magnet Rise.
In Generation V, a Flying-type Pokémon holding an Iron Ball will receive neutral damage from Ground-type moves regardless of its secondary type.
This is the appearance of the Iron Ball in the Sinnoh Underground.
An Iron Ball appeared in the Diamond & Pearl chapter. Diamond and Pearl found it amongst the metal items drawn out of the ground in Celestic Town by the magnetic field from Cyrus's Magnezone. It later appeared as an item that was used in conjunction with Lax's Fling in Platinum's Gym battle against Fantina in Mirages of Mismagius II.