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

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

Optimization · Pure Optimization
A historical worker-placement economy testing allocation efficiency against event risk.
Fallout: New Vegas leans Optimization (Pure Optimization); Predynastic Egypt leans Optimization (Pure Optimization).
Fallout: New Vegas leans clearly harder on execution.
Fallout: New Vegas
Shooter inputs with VATS assist
Predynastic Egypt
Turn-based worker placement has no physical layer
Fallout: New Vegas leans a little harder on reads, though the gap is small.
Fallout: New Vegas
Scripted factions and enemies
Predynastic Egypt
Events are scripted-historical, nothing adapts
Predynastic Egypt leans clearly harder on variance.
Fallout: New Vegas
Some loot and crit RNG
Predynastic Egypt
Event rolls and exploration outcomes inject managed risk
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Fallout: New Vegas
Faction routing, perks, builds heavily rewarded
Predynastic Egypt
Worker allocation and tech ordering is a solvable economy
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.