For example I play swordsman based classes. My original route was Sword 1 -> Pelt 1 - Hop 1 - Barb 3 - Dopple - Murm.
I took this route so I could get all the hard hitting AoE skills in the tree and mob quick and effectively, which it did. Unfortunately, Murm has attributes for its Cassis Crista that give +150% damage to Pelt/Hoplite/Rodolero skills. I thought this was additive, so those values would be less than my other hard hitting skills: Scism/Giant Swing/Cyclone (in total).
Turns out they are multiplicative, so a skill like Umbro Blow with High Guard (150%) and Cassis attribute (another 150%) would be doing over 2000% damage instead of like 860%. Even for the rodo/hoplite skills, that’s several cooldowns with about the same amount of damage as the ones I was using to mob on my other character, which warranted a reroll even though I prefered the hitboxes and style of the first one.