Year 0, the Age of Exploration
Myzelis is a planet orbiting a trinary star (called Achar, or the Mhelydraud since its sundering) along with ten other planets in the solar system, of which Myzelis is the sixth. It has two moons. One which passes between three phases (called Selisruun) and is similar in size to our own. The other moon (called Talchen) was shattered by magic long ago into two entities - an egg-like shape covered in shadowy cracks and crevices, and a brilliant halo of asteroids that encircle Myzelis like the rings of Saturn.
The planet is incalculably old - likely as old as our own - and suffused with magic that pours from its heart and forms mystical, invisible ley lines. These arcane channels represent the places where magic is at its strongest, and those who use it find it easiest to recover their powers. The people of Myzelis, in their varied cultures, tended to settle along them, and those sensitive to the magic of the ley can often follow them to meet new settlements.
Where the ley lines are weakest or absent entirely, a different phenomenon appears - the Brume of Vrokíva - a mystical obfuscation that manifests in many different ways. It disconnects communities and countries from each other and encircles them at the edges, preventing casual exploration and trade beyond the edges of the ley.