Upon completing your first task you will find yourself thrown into goblin caves. And you will begin to loot runes (and runeboards). What are these for?
Runes can be combined to cast spells. There are three runes that set the power level of a spell, and eight runes that determine the effect of a spell. You will find a magic guide over on the official forums:
https://lootbox-rpg.com/boards/viewtopic.php?t=28
You can even cast a spell on your pet (dog) that will allow it to sell your items while you continue your travel in the dungeons.