Dodge and Evasion are lackluster and require a huge investment to have a meaningful effect.
The reason for that is the binary nature of these skills. Aside from Evasion reducing AOE damage, Dodge and Evasion are simply an RNG skill, where you either do or do not get hit, and even with a 10% chance you can die to an unlucky burst or get a debuff that completely negates your stats.
The best way to buff these stats is to add additional damage reduction. Here is an example of how it can work.
While keeping the accuracy calculations as is, a damage calculation is added on top, which is split into several categories: Graze Shot, Close Shave, Minor Hit etc. You can add additional names as ideas, but the point is, that there are several thresholds that decide how much less damage you take. I'd personally divide them into 4 parts, to each it's own name. Depending on your Dodge/Evasion skill the percentage that one of the category takes effect is calculated and a flat damage reduction is applied.
So, it'll go like this (DMG reductions and chances are hypothetical):
Level 1 (Major Hit) 10% DMG Reduction. 70% chance to take effect.
Level 2 (Minor Hit) 35% DMG Red. 20% chance.
Level 3 (Graze Hit) 50% DMG Red. 9%
Level 4 (Close Shave) 90% DMG Red. 1%
These are added on top of a normal hit, in total making it 5 Levels of damage. Debuffs, such as off-balance, immobilization, incap and stuns still take effect. Only off-balance halves the % chance to take effect, immobilization reduces it by 3/4 and incap with stun work as usual. This way all builds that put points into Dodge and Evasion can still reap the benefits, while those that specialize into it can still have a fighting chance against heavy counters and not depend solely on RNG, at the same time it doesn't make heavy armor obsolete, of course IF and only IF proper balance is made. Ideally, heavy armor, should be a reliable source of consistent high damage reduction, where as Dodge/Evasion is a damage control option working on principle "you will get hurt, but you'll live."
Again, all numbers, chances and percentages are hypothetical. I personally do not know the exact, perfectly balanced stats, nor a perfectly balanced system with a smooth effectiveness progression, and am merely sharing an addition that seems a logical extension of a rather barebones system. After all, why shouldn't you be able to partially dodge a melee attack or bullet?
