head to head
Neither is simply harder - they are hard in different places. EarthBound demands more variance; Fallout: New Vegas demands more execution.

Optimization · Pure Optimization
A subversive JRPG where understanding rolling HP mechanics and PSI optimization defeats its quirky scripted encounters.

Optimization · Pure Optimization
A faction-driven RPG-shooter where build and route planning shape every ending.
EarthBound leans Optimization (Pure Optimization); Fallout: New Vegas leans Optimization (Pure Optimization).
Fallout: New Vegas leans clearly harder on execution.
EarthBound
Rolling HP meter has very mild timing implication
Fallout: New Vegas
Shooter inputs with VATS assist
Fallout: New Vegas leans a little harder on reads, though the gap is small.
EarthBound
All enemies scripted with fixed attack patterns
Fallout: New Vegas
Scripted factions and enemies
EarthBound leans clearly harder on variance.
EarthBound
PSI randomness, enemy attack variety, and encounter triggers add unpredictability
Fallout: New Vegas
Some loot and crit RNG
Fallout: New Vegas leans a little harder on optimization, though the gap is small.
EarthBound
Status effects, rolling HP strategy, and Franklin Badge usage are solvable
Fallout: New Vegas
Faction routing, perks, builds heavily rewarded
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.