Ars Magica Jumpchain

From the introduction: Do you like functional magic systems, jumper? What about medieval fantasy? I don’t mean orcs and elves, but rather, the things people actually believed in the High Middle Ages. In this world, fairies dance in the forest, cruel and playful in equal measure. Demons tempt men to their eternal ruin. Strange wizards and wise women practice esoteric rituals far from civilization. And for the common folk, the Church provides protection against a mysterious and hostile world.