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

Optimization · Pure Optimization
A dungeon-crawler RPG testing party building, skill optimization and careful mapping.

Optimization · Pure Optimization
An original RPG system where engagement optimization and passive-stacking theory dominate hard-mode encounters.
Etrian Odyssey V: Beyond the Myth leans Optimization (Pure Optimization); Pillars of Eternity leans Optimization (Pure Optimization).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Etrian Odyssey V: Beyond the Myth
Turn-based combat needs no twitch
Pillars of Eternity
Real-time-with-pause removes all twitch pressure from the player
Pillars of Eternity leans a little harder on reads, though the gap is small.
Etrian Odyssey V: Beyond the Myth
Enemies scripted, no adaptive opponent
Pillars of Eternity
All AI opponents use fixed scripted behaviour trees
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Etrian Odyssey V: Beyond the Myth
Random encounters and FOE patterns partly unknown
Pillars of Eternity
Hidden enemy immunities and ability distributions require investigation
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Etrian Odyssey V: Beyond the Myth
Class building, skill trees, and mapping drive everything
Pillars of Eternity
Per-encounter ability management and passive stacking define trial-of-iron mastery
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.