Campaign is a system for Final Fantasy XI added by the expansion pack Wings of the Goddess. The word "campaign" refers to the Alliance of Altana's efforts to combat the Beastmen armies. The system takes place all over the past areas of Vana'diel.
Using Cavernous Maws, players transport themselves twenty years in past. The Republic of Bastok, the Kingdom of San d'Oria and the Federation of Windurst's armies are available to join and players may sign up to one. Collectively the nations forces are named the Allied Forces of Altana. Battles and skirmishes frequently happen throughout the land and after receiving the effect of Sigil the player may participate in them.
However battles are not the only aspect of Campaign. Reconnaissance, supply missions, security operation and much more are available to help war with war efforts. These small scale efforts are known as "Campaign Ops".
Sigil works much like "Signet" in Conquest or "Sanction" in Besieged. In areas that are in the Campaign system, the Sigil will grant a bonus to the Allied Notes earned for killing creatures that grant experience to the player.
Sigil can be improved in duration by increasing the strong of the Ribbons and Medals. Additional bonuses, such as latent regen, latent refresh, and increased meal duration can be purchased for 50 Allied notes. The effect will remain active so long as the Sigil is in effect and only within zones on the Campaign Map.