Hero skill tree.

Doesn't the skill tree depend on the map? There's a mod that allows you to view the "skill tree" directly in the game.

If you start playing a map, the skill tree is one way; if you replay the same map (without loading a save, but starting over), the skill tree will be different. It can also depend on the map if certain skills are prohibited. But in SoD, you can't prohibit skills.