Call of Duty: World at War, also known as Call of Duty 5, employs a Rank and Challenge system that you might compare to the character leveling system in a role playing game. The fourth set of challenges are called Killer Challenges and mainly focus on using perks and special weapons that are unlocked as you rise in level. You’ll see each one has three tiers which depend upon the number of kills made at each tier. Completing these will help you earn experience points toward increasing your rank and unlocking better weapons and accessories, plus some new challenges.
Pistol Marksman I-III – Kill enemies while using a pistol.
If you like to play a sniper, then you may have already figured out it is best to move around with a pistol drawn since they fire a lot faster than your sniper rifle. You can also rack up a lot of pistol kills with the Last Stand perk.
Pistol Expert I-III – Kill enemies with a headshot while using a pistol.
Just aim for the head and shoot straight. You can do it. I sometimes like to pop people in the back of the head when I sneak up behind them, though it is still more fun and degrading to knife them.
Bolt Action Expert I-III – Kill enemies with headshots while using a bolt action rifle.
Since these type rifles have such slow reloading times, you need to learn to carefully aim your shots. Why not aim for the head, or just the upper body area? You’ll make your shot count a lot more.
Rifle Expert I-III – Kill enemies with headshots while using a rifle.
There are some very powerful rifles in this game and some of them are semi automatic, so getting a headshot isn’t too hard. Just train yourself to keep the crosshairs at the right level so that you are automatically aiming toward the enemy’s head while moving. You can practice by aiming at your fellow teammates.
SMG Expert I-III – Kill enemies with headshots while using a submachine gun.
The same principle with the rifle applies to the submachine guns. I’ve found it best to shoot in short controlled bursts, rather than just unload a clip on somebody.
LMG Expert I-III – Kill enemies with headshots while using a light machine gun.
Same as above.
HMG Expert I-III – Kill enemies with headshots while using a heavy machine gun.
This is probably the hardest of them all because the heavy machine guns aren’t known for high accuracy. I suppose if you fire enough rounds fast enough, eventually you’ll get somebody in the head.
Master Chef I-III – Kill enemies with cooked grenades.
I wrote an article on how to cook grenades in Call of Duty 4: Modern Warfare, and they work exactly the same way in this game. Basically, grenade cooking is when you hold down the throw button for a little longer in order to shorten the amount of time after release before it goes off. Just be careful not to blow yourself up.