On main land (not Silan)

Quests

Quests are special missions given by the Sage in each city. They are complicated, long missions that reward the avatar with special items. Each are available to take only once. The Fyros sage will give the Revealers of Heros quest, the Matis will seek the Treasures of Jinovich, while the Trykers wish to recover the Daggers of the Lagoons, and the Zorai are concerned about Nature Under Threat.

More (with spoilers) on Sage Missions.

Rites

Rites

A special set of missions are termed rites. There are many rites on Atys, for a variety of situations including avatar improvement and craft benefits.

Some examples include the Majestic Garden Rite, Kizoar Rite, and Kincher Rite.

The status of your rites are maintained in your encyclopedia along with your progress (shift+E ^[1], or click Task-bar system>windows>Status.>ENCYCLOPEDIA ). In all cases, you must complete some prerequisite steps before starting the actual rite. Any step may be retaken if failed, after a cooling-off period.

More on Rites, with spoilers.