City Walls are one of the core defensive buildings in Last Z: Survival Shooter. They provide your shelter with Wall Durability, add Base Power, and repeatedly become a required building for Headquarters progression.
For most players, the correct City Walls strategy is not to upgrade them after every Headquarters level. Instead, keep an eye on upcoming HQ prerequisites and prepare the Walls when they are required. During PvP, their durability also matters because repeated successful attacks can damage your shelter, eventually forcing a relocation if Wall Durability is completely depleted.
City Walls are primarily a defensive and progression building. Upgrade them before the Headquarters levels that specifically require Walls, but do not automatically spend resources keeping them equal to HQ if another upgrade provides more immediate value.
What Do City Walls Do in Last Z?
City Walls are unlocked during the early tutorial and serve several functions throughout your account progression.- Wall Durability: Determines how much structural durability your shelter has during attacks.
- Base Power: Every City Walls upgrade increases the building’s contribution to your overall power.
- Headquarters requirements: Specific HQ levels cannot be started until your Walls reach the required level.
- Defense management: The Walls are connected to shelter-defense functions and protection options.
How City Wall Durability Works
Durability represents the structural condition of your shelter. Upgrading City Walls increases their maximum durability, giving the shelter more capacity to withstand the structural damage associated with repeated successful attacks. If you lose a city defense, your Headquarters can begin burning and Wall Durability can decrease. One lost battle does not reset your account or remove your building progression. The larger risk comes from repeated attacks that continue reducing durability.What Happens at Zero Wall Durability?
If City Wall Durability is completely depleted, your shelter can be forcibly relocated to another position on the world map. This does not erase your Headquarters, heroes, research, equipment, or building levels. You may still need to deal with wounded troops, lost troops, plundered resources, Wall repair, and repositioning your shelter afterward. For that reason, experienced players usually focus less on the visual effect of a burning shelter and more on whether additional attacks are likely to continue.City Walls Levels and Power
Each City Walls level increases Base Power in addition to improving the defensive building itself. The increase becomes much larger at higher levels.| City Walls Level | Listed Building Power |
|---|---|
| 5 | 5,167 |
| 10 | 45,757 |
| 15 | 173,892 |
| 20 | 515,414 |
| 25 | 1,313,639 |
| 30 | 3,140,777 |
City Walls Headquarters Requirements
The most important reason to plan City Walls upgrades is Headquarters progression. Walls appear repeatedly as one of the buildings required before specific HQ upgrades can begin.| Target Headquarters | Required City Walls Level |
|---|---|
| HQ4 | Level 3 |
| HQ12 | Level 11 |
| HQ17 | Level 16 |
| HQ22 | Level 21 |
| HQ27 | Level 26 |
| HQ32 | Level 31 |
When approaching HQ12, HQ17, HQ22, HQ27, or HQ32, start the required City Walls upgrade while your current Headquarters construction is still running. Preparing the prerequisite early prevents your HQ progression from stopping when the current upgrade finishes.
Should You Keep City Walls at Maximum Level?
Not necessarily. City Walls improve durability and power, but they do not provide the same everyday account development as the Laboratory, troop camps, Headquarters, or other progression-focused buildings. For an account focused on efficient growth, the better approach is usually to upgrade Walls when one of three conditions applies:- They are required for your next Headquarters upgrade.
- You need more Wall Durability for active PvP.
- A construction-focused event gives you a good reason to complete the upgrade now.
Example Progression Strategy
After reaching HQ16, you already know that HQ17 requires City Walls level 16. Instead of upgrading unrelated buildings first, prepare Walls 16 so that Headquarters 17 can begin without unnecessary downtime. After HQ17 is completed, City Walls do not become an HQ requirement again until the push toward HQ22. That gives you several Headquarters levels where other prerequisites can take priority.City Walls and PvP Defense
Higher Walls provide more structural protection, but Wall level alone will not turn a weak formation into a strong defense. Successful shelter defense depends on several connected systems.Defensive Formation
Your defending heroes and troops determine the result of the battle before Wall Durability becomes the main concern. Formation strength, troop tiers, research, equipment, faction interactions, and buffs all matter.Hospital Capacity
During repeated PvP attacks, troop losses can be more damaging than Wall damage. Wounded troops can be recovered while sufficient Hospital capacity remains available, while additional losses can become more expensive if recovery capacity is exhausted.Warehouse Protection
City Walls do not make all of your resources immune to plunder. Resource protection is handled separately, making Warehouse development and sensible resource management important during dangerous PvP periods.Peace Shields
A Peace Shield prevents the problem rather than simply giving your Walls more durability to lose. If you will be offline during a major combat period and expect attacks, using protection can be much safer than relying on Wall strength alone.What to Do When Your Shelter Is Burning
Seeing the shelter burning after an attack can make players react too quickly. The important question is whether the attack is over or whether additional hits are likely.- Check the battle report and determine what happened.
- Check your wounded troops and available Hospital capacity.
- See whether hostile players are still nearby.
- Repair Wall Durability when appropriate.
- Shield or relocate if continued attacks are likely and you cannot defend safely.
- Coordinate with your alliance if reinforcements or organized defense are available.
How to Improve Wall Durability Recovery
Later research can improve how efficiently your City Walls recover. The Peace Shield research tree contains Auto Repair, a technology that increases City Wall Durability Recovery Rate as it is developed. This research becomes more relevant for players who regularly participate in PvP and experience repeated shelter attacks. Players who spend most of their time protected or outside serious combat may have more urgent research priorities first. As with other advanced research, compare the Badge cost against your current goals before investing heavily.Best City Walls Upgrade Strategy
A practical City Walls progression plan looks like this:- Complete the required early tutorial upgrades.
- Reach City Walls 11 before pushing HQ12.
- Prepare Walls 16 for HQ17.
- Prepare Walls 21 for HQ22.
- Prepare Walls 26 for HQ27.
- On servers with later progression, prepare Walls 31 for HQ32.
- Upgrade beyond immediate requirements when additional durability or event timing makes the investment useful.
Time City Walls Upgrades With Events
City Walls become increasingly expensive and time-consuming at higher levels, making event timing useful whenever you have flexibility. If a construction or building-power event is active, completing an already-needed Wall upgrade can provide both permanent progression and event points. Alliance Duel’s construction-focused phase is one example where planned building development can contribute to an additional reward track. You should not leave an important Headquarters progression path blocked for an excessive period purely to wait for an event. Instead, save flexible construction speed-ups and align them with scoring windows when the timing works naturally.Construction Speed-Ups and City Walls
Because later Wall upgrades can become long, construction speed-ups become increasingly useful. Before using them, take advantage of free timer reductions available to your account.- Request Alliance Help after starting construction.
- Apply available construction bonuses before starting a major upgrade.
- Use construction-specific speed-ups before universal speed-ups when appropriate.
- Check current event scoring before using a large stockpile.