Geoglyphs

The Coyas of Nazca, daughters of the Moon, are accomplished students of the stellar bodies and their connection with the earth. They have discovered means to amplify the influence of the planets on the terrestrial sphere through vast geoglyphs inscribed on the bare ground. As long as the enchantment of the geoglyph is active magic in the province is increased as are the ranges of rituals. Enemies fighting in a province with an active geoglyph are more easily affected by magic and have their magic resistance reduced. It is only possible to cast the ritual if you can see the land from above. Thus only flying mages can cast the spell. For the enchantment to be effective the geoglyphs must be exposed to stellar lights, so it is only castable in barren lands.

Text: Illwinter Game Design, via Dom6 Inspector