Building comparison
head to head
Fallout 3vsPortal
Fallout 3 asks more than Portal, and the gap is variance.
Fallout 3
Optimization · Pure Optimization
A VATS-heavy wasteland RPG won by perk and build optimization.
Portal
Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.
Fallout 3 leans Optimization (Pure Optimization); Portal leans Optimization (Pure Optimization).
Fallout 3Portal
Axis by axis
Execution3 vs 4
Portal leans a little harder on execution, though the gap is small.
Fallout 3
VATS-leaning combat, low aim demand
Portal
Portal placement timing modest.
Reads1 vs 0
Fallout 3 leans a little harder on reads, though the gap is small.
Fallout 3
Scripted enemies
Portal
No adversary modeling player.
Variance2 vs 0
Fallout 3 leans clearly harder on variance.
Fallout 3
Loot rolls, SPECIAL checks
Portal
Deterministic chambers; no randomness.
Optimization7 vs 8
Portal leans a little harder on optimization, though the gap is small.
Fallout 3
Perk and build planning carries the run
Portal
Pure puzzle-solving optimization.
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.