1. Zombie Samples

Zombie Samples are the primary currency used to unlock abilities and passive buffs in the Zombie Research tree. They can be collected from Zombie Safes, Zombie Containers, and Flesh Growth spots on the map. Defeating the Airport boss will guarantee a Gold-tier Sample.

2. Zombie Research:

This is where you can spend the samples you collect in raids. While you don't have too much freedom in the order you unlock new research, we still recommend unlocking the following research first:

Melee Mastery

Wasting ammo on zombies can be costly, especially in raids where you bring T5 ammo. This perk increases your melee damage against zombies, allowing you to clear them silently and without wasting bullets.

Undying Spirit

Complementing Melee Mastery, this ability restores a portion of your stamina for every zombie you kill, letting you wipe out more zombies without running out of stamina.

Pain Killer

Reduces the damage taken from zombies. Leaping and spitting zombies can drain your health bar extremely fast. With this perk, you take almost no damage.

Sustained Combat

Killing zombies restores a portion of your missing health. Fighting large zombie hordes inevitably results in taking damage. Constantly burning through your meds during a raid will put you at a disadvantage during PvP. This ability helps compensate for the damage taken from zombies.

Sample Identification

Directly increases your chances of finding red items in zombie containers. This should be the first passive you unlock if you want to maximise your income.

Vending Machine Hunter

Unlocks the chance for high-value items to drop from Vending Machines. Since these machines only work for the first player to use them, they provide a serious passive income for fast players specifically.

Hyper Intuition

Allows you to see Mutation Traces on the map. Following these traces can lead you to hidden rewards.

3. Urgent Missions & Containers

Heavy Infected Zone raids feature urgent missions that every player can see on the map. It is highly recommended that you prioritise these missions in your raids as they will reward you with loot crates and large loot crates. These crates both have very good loot tables with the large loot crate giving each player on the squad two chances to loot it.

It is also recommended that you keep an eye out for flesh growths forming on the walls and floor while you are looting. These containers, along with loot crates and large loot crates have the potential to drop No Man's Land passes which can be used to enter the S7 PvE game mode. If you are not interested in entering No Man's Land, you can also directly sell these passes for 500,000 Koen each.

Another new addition in S7 is the vending machines. You can interact with them to get food items. If you unlock the Vending Machine Hunter research, they will drop more valuable items as well.

The last important container is the mutation traces and the bio-sample. You can find mutation traces at various locations on the map, but they do nothing on their own. However, if you have the Hyper Intuition research completed, you will be able to see blue footprints leading away from them. If you follow these footprints to the end, you will find the new bio-sample. These have very similar loot tables to small safes and therefore are worth finding.

4. Signal Gun

The signal gun is a new item that is available exclusively in the Heavy Infected Zone. It can be found in random containers during raids. If you manage to find one, you can fire it into the sky in order to call down an airdrop on your location. The airdrop has 4 compartments, and every compartment has a chance to contain a Red item. Because of the high potential reward and the location of the airdrop being noticeable from afar, it is recommended that you make sure that the area you plan to use the signal gun in is clear of enemies.

5. Recommended Masteries & Season Core Loadout

With the new S7 update, new core masteries were added. You can pick one of three options in addition to your standard 12 mastery points. These are:

Hidden Compartment

Unlocks hidden compartments in containers, granting an extra search attempt. This should be the option you pick if you want to get the maximum amount of loot you can in every raid.

Acoustic Earpads

Reduces the sound-blocking effect of helmets that do not support headsets, providing an audio range increase of about 10-15m. This makes roaming much easier, especially on large maps, and facilitates map awareness on smaller maps.

Tactical Belt

Provides four 1x1 pocket attachments, allowing you to bring extra grenades or medical items. In grenade-heavy maps like Armory, having 4 extra slots for grenades or meds can give you a PvP advantage.

The addition of the core masteries massively changes how players set up their masteries. If you want to PVP but don't want to experiment too much, you can use this mastery loadout in your Heavy Infected Zone games:

FOCUS PULLER (Level 3) Increasing left and right peek speed by 18% provides millisecond advantages in narrow corridors.
SLEIGHT OF HAND (Level 3) Allows you to apply continuous pressure by reloading a massive 100-round magazine in 26 seconds. Increases your reload speed by 27%.
HEAVY MOTOR (Level 3) Reduces the movement speed reduction caused by helmets and armor by 35%.
PORTER (Level 3) Directly increases the weight limit by 10 kg. People often run heavy armor, and looting even a tiny bit can put you in the yellow weight penalty zone. This perk helps you to move without penalty even when carrying some heavy items.
ACOUSTIC EARPADS Reduces the sound-blocking effect of helmets.

If you are more interested in maximising your economy by increasing potential gains and minimising losses, you can use the following build:

PORTER (Level 3) Directly increases the weight limit by 10 kg, protecting you from extreme overweight penalties.
EFFECTIVE LOOTING (Level 3) Grants a 20% chance to skip the searching phase when opening containers.
VINSON’S FRIEND I (Level 3) Has a 10% chance to return your weapon even if you fail to extract.
EMERGENCY EVASION (Level 3) Useful for quickly escaping and recovering after taking damage in sudden ambush and combat situations.
HIDDEN COMPARTMENT To maximize loot yield and find hidden valuables.

6. Recommended Weapons

The S7 update also changed the established meta for guns by adding two new weapons and the new seasonal attachment system. Here are some of the new contenders for meta status that you might want to try:

A545 View Builds

With its high RPM and easy controllability, this gun easily became one of the top meta weapons. With 5.45x39 BS ammo, it can easily penetrate distant targets.
MPX with Vulcan Barrel View Builds

This MPX attachment introduced with the new season synergises very well with Dum-Dum ammo by increasing the damage bullets deal to unarmored enemies while reducing the damage they deal to armor.
FAL with Burst Kit View Builds

This attachment, which lowers the FAL's RPM, increases the weapon's accuracy, turning it into a fully automatic sniper rifle. When used with M61 and M62, the FAL turns into a highly effective weapon.

7. No Man's Land

Unlike the hostile sector in S6, this PvE mode is extremely simplified and calm. Scavs have terrible accuracy and deal very low damage. The main thing that will give you trouble in No Man's Land is the zombies swarming you in hordes, so it is recommended to bring 120-180 rounds of T3 ammo with you. If you have made upgrades in the skill tree, this number can be even lower.

Your primary loot targets in No Man's Land are bio-samples. Their loot quality is comparable to a small safe, and you can find valuable items or pure samples required for upgrades inside them. Important bio-samples can be found in different locations in every raid. If you want to find them more easily, you need to unlock the Hyper Intuition ability. By following the footprints on the map, you can easily find them. Additionally, completing in-raid missions provides extra samples and valuable equipment, thereby increasing your profit. The general loot rate of No Man's Land is roughly the same as the Lockdown game mode. You can use keys, but finding high-value items is not guaranteed.

Other things you should loot in No Man's Land are document boxes and office drawers. Inside these, you can find the blueprints required for the workbench.

As soon as you enter the raid, target the vending machine routes and urgent extermination missions. Quickly gather loot with Vending Machine Hunter and utilize the double search attempts from mission crates. Don't hoard the Zombie Samples you find; invest them immediately into Sample Identification in the research tree to maximize your Red item drop chances early on.

You can follow this route to collect all of the safes efficiently.

8. TL;DR

The Arena Breakout: Infinite (ABI) S7 Heavy Infected Zone drops players into zombie filled maps where they must collect Zombie Samples to unlock permanent survival and economic buffs in the Zombie Research tree. Raid profitability relies on prioritizing public Urgent Missions for high-tier crates, searching Flesh Growths for No Man's Land passes, utilizing the new Signal Gun for airdrops, and following mutation traces to hidden bio-samples. Players can further optimize their loadouts by adopting new core masteries like Hidden Compartment for maximum loot yield or Acoustic Earpads for PvP awareness, alongside newly dominant weapons like the high-RPM A545, Vulcan-barrel MPX, and burst-kit FAL. Those who secure a pass can enter the No Man's Land PvE mode, a lower-stress environment focused entirely on clearing zombie hordes with mid-tier ammo to safely farm bio-samples, research currency, and workbench blueprints.