Before a round begins, you can choose one of four characters to play as and one of four roles — Control, Medic, Offense, or Support — each with a preset Loadout that includes a starting weapon, an explosive, a Special Ability, and three Mods.

When you start Nazi Zombies, you'll be armed with a few grenades and a pistol. The first round begins slowly with a few low-level zombies shambling toward you. As you progress, more waves of zombies emerge that include more powerful zombies. As you clear out waves, you earn Jolts, which are used to purchase weapons and power-ups. Be on the lookout for weapon lockers and power-ups to help you even the odds and improve your chances of survival.

Guns

Progressing through Nazi Zombies nets XP, allowing you to rank up and unlock access to better weapons. Choose from an assortment of pistols, assault rifles, and shotguns. Each of these weapon categories has its strengths and drawbacks depending on your style of play, the number of zombies after you, and the type of zombie.

Shovel

In the Prologue you'll find the Shovel, which you can either carry as your Primary weapon or wield as a melee attack. The Shovel can be effective against lower-level zombies, but as more powerful zombies emerge or the volume of zombies increases, the Shovel can leave you vulnerable. Still, Shovel kills pay out more Jolts than gun kills.

Explosives and Knives

Explosive devices can be particularly useful against groups of zombies. The tradeoff, however, is explosion kills are worth fewer Jolts than kills with a gun or the Shovel. There are five types of explosives in Nazi Zombies, four of which you can add to your loadout.

• MK 2 Fragmentation – A standard frag grenade that destroys targets with a burst of flying shrapnel. Frag grenades can be cooked so you can time its detonation.
• Sticky Bomb – A lethal bomb that sticks to targets before detonating.
• Satchel Charge – A lethal remote-detonated explosive that must be stuck to a surface before it can be detonated. Great for setting traps.
• Bouncing Betty – A pressure-activated mine that jumps into the air before detonating. Best used defensively.
• Jack-in-the-Box – found in Mystery Boxes, a Jack-in-the-Box will play a tune that attracts nearby zombies before exploding.

You can also choose to arm yourself with Throwing Knives. A single knife can take down low-level zombies and, like the Shovel, offer more Jolts than gun kills. Thrown knives that miss a target can be picked up and thrown again.

Camouflage – Makes you invisible for a short period and causes zombies' eyes to glow.

• Field Medic – Revive fallen allies twice as fast
• Survivalist – Gain one Armor point
• Exfiltration – Camouflages a revived teammate for five seconds
• Saboteur – Increases grenade damage
• Serrated Edge – Melee attacks inflict a damage-over-time effect on zombies, dealing 3% of the zombie's maximum health to it every 1.5 seconds for 30 seconds

Freefire – Gives you infinite necromantic energy ammunition for 20 seconds, then reloads your current weapon.

• Marksmanship – Triples your weapon's damage multiplier for headshots
• Explosives Handler – You and your teammates receive two grenades
• Ammo Carrier – Gives a clip of ammunition to nearby teammates
• MK. II – Temporarily turns your weapon into an upgraded weapon
• Squad Tactics – Grants you and nearby teammates 150% bonus to your weapons' headshot multiplier

Frontline – Causes all zombies in the area to pursue you while giving your weapon double damage.

• Resilient – Increases your health recovery time
• Vicious – Increases your damage bonus to 300%
• Determination – Receive an additional two points of Armor
• Team Effort – Extends Frontline's damage bonus to your teammates
• Punishment – Zombies automatically die when they hit you

Shellshock – Your character emits a radial burst of energy that stuns, knocks down, and damages zombies. Zombies remain stunned until the Special Ability meter runs out.

• Breathing Room – Shellshock receives a 200% bonus to knockback and increases the burst radius by 150%
• Protector – Teammates in Shellshock's burst radius receive one Armor point
• Fiery Burst – Zombies hit by Shellshock are set on fire.
• Exploit Weakness – Zombies stunned by Shellshock take triple damage
• Defibrillate – Fallen teammates in Shellshock's burst radius are revived.

Mittelburg contains weapon lockers, kiosks that dispense an assortment of firearms in exchange for Jolts. A weapon picked up from a weapon locker replaces your currently equipped weapon and comes fully loaded. You can also go back to the locker to restock the weapon's ammo in exchange for half its original Jolt cost.

Character boosts and upgrades are also available in Nazi Zombies. Purchased from Blitz Machines scattered throughout Mittelburg, Blitzes provide powerful, permanent, and passive bonuses.

Your character can hold and receive bonuses from four Blitzes at a time by default, and if you pick up a new Blitz, it takes the place of your oldest Blitz.

Purchasing a Blitz leaves your character vulnerable for a few seconds while the Blitz upgrades take effect, so it's best to time your Blitz purchases properly.

• Armor (500 Jolts) – Each point of Armor negates one lethal incoming attack that would have killed you otherwise.
• Faustblitz (2,000 Jolts) – Deal more melee damage.
• Kugelblitz (2,000 Jolts) – Weapons inflict double damage.
• Laufenblitz (2,000 Jolts) – Move 7% faster and receive infinite sprinting stamina.
• Lebenblitz (500/1,500 Jolts) – If playing solo, your character can auto-revive up to three times before the Blitz runs out. If playing in a group, you revive teammates twice as fast.
• Schildblitz (2,000 Jolts) – When reloading, your character produces a burst of electricity that stuns and damages nearby zombies.
• Schnellblitz (3,000 Jolts) – Reload twice as fast.

Once you've opened the bunker door in the first part of Nazi Zombies, you'll gain access to Mystery Boxes, which can be purchased for 1,000 Jolts. Along with Jack-in-the-Boxes, Mystery Boxes can include weapons available in weapon lockers, weapons that aren't available in loadouts (such as LMGs), a "rocket revolver" called the Fliegerfaust, and more.

Buried in the Catacombs under Mittelburg is an Upgrade Station where you can infuse your current weapon with Geistkraft. Infusing a weapon renames it and upgrades its damage, maximum ammo, and clip size. On top of that, rifles become more accurate when fired from the hip, machine guns become lighter to improve your movement speed, and larger guns receive improved handling. Some weapons also receive additional unique bonuses such as burst fire and explosive rounds.

Upgraded weapons cost more Jolts to reload and will disappear if you swap it out for another weapon from a weapon locker.