Criteria for Shooting
There are different qualities to expect from human combatants using real projectile weapons. These characteristics generally apply to game players, too, and become restrictions on the AI:
Reliable— Firing a weapon should be done in such a way to prevent self-injury. Constant measures should be taken to avoid this.
Smooth— When aiming for a target, adjustments are done in a realistic fashion, as you would expect from humans (a.k.a. leading). This contrasts with the mechanical step-by-step aiming.
Effective— People do generally prove accurate at aiming, especially with training. Although even when humans miss a target, they do so in a justifiable way (when longer predictions are required).
These can serve as a set of criteria for the evaluation of AI nonplayer characters (NPCs).