head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is execution, and it is a single point.

Optimization · Pure Optimization
The genre-defining loot ARPG whose builds, runes, and trade economy players still optimize decades later.

Optimization · Systems & Chaos
A comedic roguelike where absurd skill trees and crafting combos carry you past lutefisk and Diggle hordes.
Diablo II leans Optimization (Pure Optimization); Dungeons of Dredmor leans Optimization (Systems & Chaos).
Diablo II leans a little harder on execution, though the gap is small.
Diablo II
Positioning and potion reflexes, little else physical
Dungeons of Dredmor
Turn-based; no physical demands
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Diablo II
Monster AI is fully mappable
Dungeons of Dredmor
No adaptive opponent
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Diablo II
Loot RNG and random maps drive the grind
Dungeons of Dredmor
Random floors, loot, and crafting drops vary runs
Diablo II leans a little harder on optimization, though the gap is small.
Diablo II
Builds, breakpoints, rune economy, magic-find routing are the game
Dungeons of Dredmor
Skill-tree synergies and crafting are highly solvable
A matching score does not mean a matching test. Two games can both sit at 10 on execution and demand completely different things of you - which is why the reasoning above matters more than the number beside it.