head to head
Neither is simply harder - they are hard in different places. Fallout: New Vegas demands more execution; Knights of the Old Republic demands more variance.

Optimization · Pure Optimization
A faction-driven RPG-shooter where build and route planning shape every ending.

Optimization · Pure Optimization
A d20 Star Wars RPG where Force power selection and alignment routing define clear optimal paths.
Fallout: New Vegas leans Optimization (Pure Optimization); Knights of the Old Republic leans Optimization (Pure Optimization).
Fallout: New Vegas leans clearly harder on execution.
Fallout: New Vegas
Shooter inputs with VATS assist
Knights of the Old Republic
Pseudo-turn-based d20 combat removes all twitch; timing aids exist but minor
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Fallout: New Vegas
Scripted factions and enemies
Knights of the Old Republic
All enemies follow scripted AI behaviour trees without player modelling
Knights of the Old Republic leans clearly harder on variance.
Fallout: New Vegas
Some loot and crit RNG
Knights of the Old Republic
Loot rolls and pazaak draws provide hidden information layers
Knights of the Old Republic leans a little harder on optimization, though the gap is small.
Fallout: New Vegas
Faction routing, perks, builds heavily rewarded
Knights of the Old Republic
Force power selection, feat prerequisites and light/dark routing are systematically 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.