Character progress in Eldiron is done via level trees. A Level Tree is a node you can insert into any Systems object. It connects to a chain of Level Node nodes, each representing a node which gets executed when a specific experience level is reached.
A level tree is automatically discovered and used in the system class object of your character. However you can Point Eldiron to custom level tree node locations using the Set Level Tree node in a startup tree of your character.
This simple level tree with only two levels is an example of a level tree. The level tree node enables you to enter the message which is shown to the player every time his character gains experience.
The level nodes represent each level, the Starts at parameter displays the total experience needed to gain to this level, the Message attribute is the message which is displayed to the user when he gains the level and finally the Script parameter is the script which gets executed when the user reaches this level, in the script you can modify the characters sheet as needed.
As discussed Increasing Experience you can add experience to the character using the
sheet = increase_experience_by(sheet, 10); function.