Dia is a status effect in Final Fantasy XI that reduces Defense by a percentage and deals light elemental damage every tick that it is active. Though it is usually caused by the spell of the same name, it can also be applied as a side effect of certain NPC abilities.
Players may not inflict Dia and the dark-aligned Bio on a target at the same time. Bio's presence prevents the application of Dia unless the latter is a higher rank. Casting Dia III will remove Bio II and apply a Dia status effect, for example, but Dia II would fail under the same circumstances. Monsters do not abide by this convention, however, and may sometimes afflict players with simultaneous Bio and Dia effects.
Periodic damage dealt by Dia status will awaken sleeping characters. Although the initial damage of the spell's application can be resisted, the status effect itself cannot be avoided unless the victim has complete magic immunity. In addition to being canceled by a higher-ranking Bio, Dia status can be removed by Erase, Benediction, Healing Waltz, or Afflatus Misery-enhanced Esuna. The healing properties of a Mog House are also sufficient to dispel the affliction.
|Dia status effect|
|Source||Defense* Defense reduction||Damage* Damage per tick|
|Diaga II* Not available to players.||10.35%||2|
|Diaga III* Not available to players.||15.23%||3|