The skill packs downloadable content were originally pre-order bonuses at various shops, but were later released as purchaseable content.
There are free skill packs of each of them, which are used for people who haven't purchased the packs but are in a coop game with somebody who has them.
Ninja Skill Pack
Includes four pieces of Ninja clothing for Chuck to wear.
- Head: Ninja Cowl - "Classic assassin headgear"
- Face: Ninja Mask - "Hides your identity from your enemies"
- Feet: Tabi Boots - "Perfect for sneaking about"
- Body: Ninja Shozoku - "Comfort and stealth, all in one package"
Wearing all four pieces of clothing at the same time unlocks different attacks for the following weapons
- Katana Sword
- Laser Sword
- Magician Sword
When wearing any pieces of the outfit, Chuck is undetectable to ordinary zombies. The psychopaths and mutated zombies are unaffected though.
Stacked throwing items also do more damage and the throwing speed is increased.
Sports Fan Skill Pack
The following pieces of clothing are included with this pack.
- Sports Fan Helmet
- Sports Fan Clothes
- Sports Fan Cleats
Wearing items from this skill pack give Chuck the following bonuses
- Increased Power for All Sports Weapons: Baseball bats swing harder, balls bounce more, and the years of armchair coaching pay off when sports-themed weapons become greater tools of zombie destruction.
- Unique Attack: Grab a football and plow down the undead competition with a powerful running stiff-arm.
- Better Health Recovery: Who can go into the big game without half-time snacks? Chuck regenerates one extra health block for each food or drink item he consumes. This is added in to other bonuses: a Snack normally only heals one health bar, but with the SF outfit, it heals two. If Chuck carries Health 2, it will heal three. (Note:The health block is added after any health magazines you have.)
- Permanent Alcohol Tolerance: Chuck will no longer get sick when knocking back one too many alcoholic beverages such as beer, wine, vodka, etc. This is especially handy when combined with the Beer Hat.
- Increased Gambling Winnings: Your luck goes further than the field. Sports Fan Chuck will gain $100 more whenever he wins in the casinos (added before any other bonuses).
- Chuck's running speed increases.
Soldier Skill Pack
The soldier skill pack includes the following pieces of clothing.
- Soldier Goggles
- Soldier Facepaint
- Soldier Boots
- Soldier Clothes
When wearing the soldier costume you will have the following bonuses
- Double ammo.
- Increased shooting accuracy, the LMG will have no excessive recoil even in full automatic fire.
- More firepower and increased headshot accuracy.
- Chuck will also have a new special attack when using automatic weapons.
Psycho Skill Pack
The psycho skill pack includes the following pieces of clothing for Chuck to wear.
- Head: Psycho Hair - "A visage that reflects your weary work."
- Face: Psycho Mask - "Being crazy is wrong, but it feels so right."
- Body: Psycho Shirt - "Blood stains are a badge of Honor."
- Feet: Psycho Boots - "Who said serial murder can't be stylish?"
Wearing any piece of clothing from the pack grants Chuck the following bonuses
Increased attacks and damage from the following weapons:
- Power Drill
- Chef Knife
- Large Wrench
- Cement Saw
- Mining Pick
- Meat Cleaver
Special Attacks: The Meat Cleaver, Mining Pick, and Machete gain special animations.
Reduced Damage: Your years of killing have built up a natural tolerance to pain.