Gunplay: Spread is huge while moving. Let go of your movement keys, or tap the opposite direction to counter-strafe, then shoot. Rifles follow a fixed recoil pattern (the AK climbs, then pulls left, then right); pull down against it to control the spray. Short bursts beat full-auto spraying.
Penetration: Bullets punch through wooden doors, crates, thin walls and sheet metal, losing damage on the way. Headshots deal ×4 damage; armor and helmets cut damage sharply.
Sliding: Press crouch at near-full sprint speed to get a burst of speed and drop your profile. Jump out of the slide to keep the momentum.