From the introduction:
In 597, Queen Fredegund solidified her hold over the Franks. the Avars began their siege of Tomis, and Mangelesha ascended the throne in India. In our world, the year ended quietly. In another world, the sky tore open to nothingness, and the shards first fell.
From Europe and Asia to Africa and Americas, shards fell. The first was a scattering, but more shard falls were to come. Where the event itself left people to wonder what this prodigy meant, it was nothing compared to what happened when man picked up his first iridescent black crystal.
Shards presents a simplified "d6" version of the Krendel system but otherwise focuses primarily on setting development.