Classes are the eight Saga-mode roles that can be played in Tribes of Midgard. Warrior and Ranger are available from the start. The others will need to be unlocked by completing its corresponding Class Challenge.
As you defeat creatures, harvest resources, activate shrines, and upgrade the characters at the village, your yellow experience bar will increase until advancing to the next level earning you a Blessing. Spend your first Blessing by choosing a class and earn the default skill in that class's skill tree. Future blessings may be spent as you choose to build your skill tree.
See how close you are to unlocking a class by checking the Progress button in the Main Menu.
Survival[]
In Survival mode, Blessings can be spent on a skill tree made up of Skills from all the Classes.