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
An open-world RPG mostly about discovering and stacking exploitable progression systems.

Optimization · Pure Optimization
An open-world mech JRPG whose combat rewards deep system and build optimization.
The Elder Scrolls V: Skyrim leans Optimization (Pure Optimization); Xenoblade Chronicles X leans Optimization (Pure Optimization).
Xenoblade Chronicles X leans a little harder on execution, though the gap is small.
The Elder Scrolls V: Skyrim
Combat is forgiving; aim and timing rarely punish you.
Xenoblade Chronicles X
positioning and arts timing in combat
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
The Elder Scrolls V: Skyrim
Enemy AI is scripted and exploitable; not adaptive.
Xenoblade Chronicles X
solo JRPG, no adapting opponent
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
The Elder Scrolls V: Skyrim
Loot tables and leveled lists inject mild randomness.
Xenoblade Chronicles X
drop rates and crit rolls
Xenoblade Chronicles X leans a little harder on optimization, though the gap is small.
The Elder Scrolls V: Skyrim
Skill stacking, enchant loops, and exploits are deeply solvable.
Xenoblade Chronicles X
deep build/skill/gear system to optimize
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.