Source: Soldiers of Brass, pg(s). 55
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Native to the Material Plane, jann can visit any Elemental Planes but cannot survive there for more than a couple of days. Because of this, they are naturally nomadic, trading goods and transporting people between the Material and Elemental Planes.
Jann are composed and gregarius but also suspicious and proud, and quick to anger if they feel insulted. Jann have a tradition of hospitality and rarely turn away creatures that need shelter or sustenance, but usually expect reciprocation for their kindness. Despite their weak magic compared to other genies, jann are creative in its application, focusing on interplanar travel.