A runestones is a magical device containing a spell that can be cast without prior knowledge of the spell or even the magic type. To use one, you should focus <runestone> to figure out the type of rune it is, then you can rub <runestone > to get the spell into your mind before casting it. You may need to focus <runestone> 100 to charge it before rubbing it and casting the spell. Runestones tend to wear out over time, so you'll only get a few uses out of them before they crumble to dust, but they're also relatively easy to find, as critters drop them and several stores, including the artificer in Shard, sell them. They're also an excellent, if not essential, method of learning your primary magic until you can cast spells of your own.