head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is variance, and it is a single point.

Optimization · Systems & Chaos
A 3D mystery adventure where Gabriel Knight untangles a vampire kidnapping and the Rennes-le-Château grail enigma.

Optimization · Pure Optimization
Bleak Ellison adaptation where five tortured souls face a sadistic AI.
Gabriel Knight 3: Blood of the Sacred, Blood of the Damned leans Optimization (Systems & Chaos); I Have No Mouth, and I Must Scream leans Optimization (Pure Optimization).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Gabriel Knight 3: Blood of the Sacred, Blood of the Damned
3D camera fiddling, but no real dexterity test.
I Have No Mouth, and I Must Scream
Pure point-and-click, no dexterity
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Gabriel Knight 3: Blood of the Sacred, Blood of the Damned
Vampires and treasure hunters are scripted figures.
I Have No Mouth, and I Must Scream
AM is scripted despite the menace
Gabriel Knight 3: Blood of the Sacred, Blood of the Damned leans a little harder on variance, though the gap is small.
Gabriel Knight 3: Blood of the Sacred, Blood of the Damned
Rennes-le-Château mystery hides clues across timed days.
I Have No Mouth, and I Must Scream
Obscure solutions hidden until discovered
I Have No Mouth, and I Must Scream leans a little harder on optimization, though the gap is small.
Gabriel Knight 3: Blood of the Sacred, Blood of the Damned
Le Serpent Rouge geometry puzzle epitomizes fixed deep solving.
I Have No Mouth, and I Must Scream
Puzzle chains and ethical-path knowledge
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.
full breakdown
Gabriel Knight 3: Blood of the Sacred, Blood of the Damned →
full breakdown
I Have No Mouth, and I Must Scream →