That means you can’t combine two elemental skill books together. To use Skill Book combo abilities, you’ll need at least one level in both types of magic - combos only seem to work when combining elemental magic and non-elemental magic. There’s a ton of awesome abilities out there, so instead of going in blind, here’s a full list of Level 1 Skill Book combos. In-game, there’s no way to know what you’ll get before combining two skills books. Divinity: Original Sin 2 adds plenty of interesting wrinkles to the western-RPG formula, and one of those wrinkles is the ability to combine two skill books and create an entirely new ability.
