Skill System
Description
In the world of Sevens, every person possesses a single skill — a gift of the gods. Skills fall into three categories by the color of their matching jewel: red are vanguard (melee), yellow are rearguard (ranged and magic), and blue are support. A skill manifests around the age of seven or eight but can only be used in full from the age of ten.
Jewels are a lost technology that let a person's skill be recorded into a stone and later used by another bearer. Magic devices arose as a more accessible substitute for jewels and are now more widespread, though they fall short of jewels in power. House Walt's Blue Jewel is the rarest kind of example — an artifact that accumulated seven generations of support skills and evolved into something greater.