Let’s use the barbarian’s Whirlwind as an example. Right now in the skill tree you can allocate up to 5 skill points into the skill. There should be different bonuses for maxing out a skill along with going above the max rank with additional +skills from items.
I’ve added an example of a bonus for reaching Rank 5, Rank 8, and Rank 10 (I just thought that those seemed appropriate, I don’t even know if rank 10 of a skill is possible yet).
Rank 1: +10% dmg
Rank 2: +10% dmg
Rank 3: +10% dmg
Rank 4: +10% dmg
Rank 5: +10% dmg (bonus: 25% radius)
The below ranks are only obtainable by using items with +Ranks of Whirlwind and should provide additional bonuses for hitting different ranks above and beyond what is possible by just using skill points in the tree.
Rank 6: +10% dmg
Rank 7: +10% dmg
Rank 8: +10% dmg (bonus: 25% movement speed while channeling)
Rank 9: +10% dmg
Rank 10: +10% dmg (bonus: gain % damage equal to your movement speed)
Obviously I’m just using the bonuses as an example but I think this would enhance the skill tree and make finding those types of affixes very interesting.