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

Execution · Practiced Mastery
A gritty WWII Call of Duty that introduced the Zombies mode.

Execution · Practiced Mastery
The trilogy capper with the series' most polished competitive multiplayer.
Call of Duty: World at War leans Execution (Practiced Mastery); Gears of War 3 leans Execution (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Call of Duty: World at War
Twitch gunfights in fast multiplayer lobbies
Gears of War 3
Refined wallbounce and gnasher precision dominate versus
Gears of War 3 leans a little harder on reads, though the gap is small.
Call of Duty: World at War
Human opponents reward positioning prediction
Gears of War 3
Reading human rotations and bait plays matters
Call of Duty: World at War leans a little harder on variance, though the gap is small.
Call of Duty: World at War
Random lobbies, spawns, and zombie waves
Gears of War 3
Horde waves vary slightly
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Call of Duty: World at War
Perk loadouts and map control are learnable
Gears of War 3
Map spawns and loadout meta are mappable
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.