Experience Points

I use milestone XP. At the end of each session, the GM awards each PC a number of XP points between 1-10 depending on the events that occurred that session. When PCs reach 10 XP, they can level up reset their XP to 0 the next time they have a period of a week or more in a safe place with a tutor or other way to gain more power.

Generally, it is expected that the max level for mortals in the land of Chardenfell is only 6th level. To go beyond this, an extraordinary power source must be found in world during the narrative of the campaign. There are rumors of ancient power sources, but they are often no more than tall tales and myths. After 6th level, advancement will only be possible after finding such a mythical and elusive power source.

Resting

Whenever a PC takes a long rest. They may choose whether or not they wish to gain the benefits of a long rest. In order to gain the benefits, they lose half of an XP point towards their next level. This represents the toll it takes for the mind and body to recover from intense exertion.