Zenless Zone Zero's Hollow Deep Dive System is the main game mode where players complete main missions and side missions for rewards. In 2026, it is still the central PvE loop: a player picks a commission, moves Bangboo Eous across a Board of televisions, fights Ethereals, and collects Films, Dennies, upgrade materials, and other resources. The mode has several branches, and each one serves a different purpose. Some are story-heavy, some are quick combat checks, and one is a roguelike endgame grind. The trick is knowing which commission type to run when.

Main Commission: The Backbone of Progression

The Main Commission follows Zenless Zone Zero's main storyline. To avoid spoilers, the details stay vague here, but the structure matters. Main Commissions allow trial characters, such as story-limited Agents like Nekomata. Players can toggle Story Mode at the bottom left to switch between trial Agents and their own roster. This toggle does not affect the storyline, so it is purely a comfort setting.

Many stores and other game modes are locked behind Main Commission progress. That makes this branch the first priority for any new player. Completing Main Commissions also grants free characters: Anby, Billy, Nicole, and Ben. They are only A-Rank Agents, but free is free, and they can carry early teams.

Players can revisit old stories through the Commission Log on the shelf beside the television. Replaying cutscenes is nice, but the real bonus is claiming rewards after completion. Those rewards include Films and Dennies. The claim icon is the small ZZZZ icon at the bottom left, which is easy to miss at first glance.

The Board, Bangboo Eous, and Terrain

Every Main or Side Commission stage sends the player through many televisions, officially called the Board. The player controls Bangboo Eous and moves through different terrain types. Some tiles heal characters, some collect observation data, and the most important ones trigger fights against enemies and bosses. Red televisions usually mean combat, and those battles are where the real rewards and risks sit.

The Board is not just a map. It is a resource-management puzzle. A player has to decide whether to chase extra data, heal a hurt squad, or push toward the boss. That decision-making gives Hollow Deep Dive more texture than a simple stage-select screen.

Pressure, Corruption, and When to Bail

Certain stages add Pressure and Corruption. Every step through Hollow terrain increases Pressure by 10. When Pressure reaches 100, the squad suffers Pressure overload and gains a random Corruption. Pressure then resets to 0.

Corruption works like a debuff, though some Corruptions are arguably buffs. For example, Corruption: Sharpened Pain gives both enemies and allies a Crit DMG Bonus. That is fair, and many players would call it a positive trade. Other Corruptions hurt combat or exploration, so players should check the Corruption tab for details.

Once a squad accumulates five Corruptions, further Pressure accumulation causes proportional HP loss. If squad members drop too low, exploration ends early. That is the fail state. Players can check which stages have this mechanic by looking at the pressure bar in the HDD. The bar reflects Ether activity, and higher activity means more intense pressure.

Hollow Activity Level	Pressure Effect
Low	No Pressure
Moderate	Certain areas may cause Pressure
High	All areas cause Stress

Side Commissions: Small Tasks, Big Unlocks

Side Commissions are exactly what the name suggests. Players start them by exploring the open world and talking to NPCs with obvious marks above their heads. Once accepted, the commission appears in the Side Commission list. Completing them gives the corresponding rewards.

Some Side Commissions unlock stores in the open world, such as 141 Convenience Store and Waterfall Soup. That makes them more valuable than their immediate rewards suggest. A player who ignores Side Commissions may miss convenient shops, upgrade paths, or quality-of-life services. It is worth collecting them early and clearing them when the main story slows down.

Rally Commissions: Pure Combat, Pure Rewards

Rally Commissions are the battle-focused mode. There is no television navigation. The player just defeats enemies left and right. As Inter-Knot Level increases, new difficulties unlock: Basic, Intermediate, Advanced, and Expert. Harder commissions give better rewards but require more Battery Charge.

There are four types of Rally Commissions:

• Perfect Assist: Metro Zone

• Vital View: Scrapyard Zone

• Depth Exploration: Construction Zone

• Triathlon Rally

Some Rally Commissions have special Commission Features. These grant effects to all allies during the commission, and the effect can be a buff, a nuisance, or both. Players should check the Details screen before starting.

Completing Rally Commissions yields Plating Agents, which are needed to Tune Drive Discs, as well as Inter-Knot Credits. First-time clears give bonus Film and other upgrade materials. Advanced and Expert Rally Commissions give Rally Records, which are needed for advanced Agent Skills. Mini Cargo Trucks also hide along the way, and opening them grants bonus rewards.

Hollow Zero: The Roguelike Endgame

Hollow Zero unlocks after completing the first Rally Commission, Perfect Assist: Metro Zone - Beginner, when Shepherd visits the store and relays the news. From the official announcement, players also receive the first exploration commission for Hollow Zero after completing Earlybird Ticket to Safety. This mode is Zenless Zone Zero's answer to a roguelike endgame, similar in spirit to other HoYoverse endgame modes.

Only one Agent can enter the battle at first as the Leader. Other Agents can support once more areas have been explored and stabilized. Before entering Hollow Zero, the player designates one Agent as Leader. At the Edge, they can designate two Agents as Backup. If no Backup is added, those Agents cannot be called later. As exploration goes deeper, more Backup slots open.

When entering Stable Areas, the player can make a Random Call to bring in one Backup Agent as reinforcement. If support is not needed immediately, they can record the Agent's message to the Reinforcement Beacon Bangboo Plug-In. Later, a Reinforcement Beacon can instantly call a Backup Agent for help.

Hollow Zero is divided into four areas based on depth: the Edge, Interior, Heartland, and Core. Each area has several floors. Defeating enemies at the end of a floor completes its exploration. The exit on the final floor has a Final Threat, and clearing it completes the whole area.

The combat-enhancing effects in Hollow Zero are called Resonia. They work like blessings from another roguelike mode. When a player has four or eight Resonia from the same category, an extra advanced Resonium is generated. The bottom of each Resonia shows Already Owned: 00 Card. Once four cards are reached, the bonus buff is automatic. The Resonium Inventory on the left shows all owned Resonia and their effects.

Every floor cleared in Hollow Zero gives Etheric Matter samples. Even if the player fails to defeat the final enemy, they still get a certain ratio of samples. During the investigation period, investigation rewards can be claimed based on the number of samples collected.

Final Thoughts for 2026

Hollow Deep Dive remains a layered system. Main Commissions unlock the world and free Agents. Side Commissions unlock shops and open-world conveniences. Rally Commissions provide focused combat and essential upgrade materials. Hollow Zero delivers the long-term roguelike challenge. A player who understands the differences will spend Battery Charge efficiently and avoid the frustration of running the wrong mode.

The safest route is simple: clear Main Commissions until the world opens up, grab Side Commissions when stores or rewards matter, use Rally Commissions for Plating Agents and Rally Records, and treat Hollow Zero as the endgame test. Pressure, Corruption, and Resonia may look intimidating, but they are just systems to manage. Once the rhythm clicks, the Hollow Deep Dive System becomes the most rewarding part of Zenless Zone Zero.

According to coverage from Rock Paper Shotgun, strong PvE game loops tend to reward players who can distinguish between “progression” content and “farming” content, which maps cleanly onto Zenless Zone Zero’s Hollow Deep Dive branches: push Main Commissions to unlock systems and free Agents, clear Side Commissions when they open practical services and shops, spend Battery Charge on Rally Commissions for targeted upgrade materials, and treat Hollow Zero as the scalable roguelike layer where build choices (Resonia) and risk management (Pressure/Corruption) define long-term efficiency.