Zombie Invasion
Zombie Invasion is a recurring event in Last War: Survival where invading zombies appear across the World Map. Defeating them rewards Courage Medals, which can be exchanged in the event Trade Store for valuable items. Occasionally, defeating an invading zombie will also spawn a powerful Zombie Boss that requires an alliance rally to defeat.
Once your server reaches Season 2, defeating Zombie Bosses also contributes toward the Glacieradon alliance challenge. This guide focuses on the Zombie Invasion event itself and explains how Zombie Boss summoning works.
How the event works
- Defeat invading zombies to earn Courage Medals.
- Courage Medals can be exchanged in the Trade Store.
- Every defeated zombie has a random chance to spawn a Zombie Boss.
- Zombie Bosses are significantly stronger than regular zombies and require rallies to defeat.
- Damage dealt to Zombie Bosses is recorded on the event leaderboard. Higher total damage earns better ranking rewards.
- Everyone who participates in defeating invading zombies receives an Invasion Defender reward when the event ends.
- Newly spawned Zombie Bosses are protected for 10 minutes, during which only the alliance that discovered them can rally them.
Zombie Boss Summoning Levels
Every player has a hidden value called Summoning Level.
This value determines the level range of every Zombie Boss you can spawn. It is unique to each player and increases over time based on specific conditions.
What affects Zombie Boss levels?
Zombie Boss levels are determined only by your personal Summoning Level.
The following have no effect on Zombie Boss levels:
- HQ Level
- Commander Power
- Hero Strength
- Alliance Power
- Server Age
- VIP Level
- Money spent
Summoning Formula
Whenever you spawn a Zombie Boss, the game randomly selects its level based on your current Summoning Level.
Minimum Boss Level = Summoning Level - 15
Maximum Boss Level = Summoning Level + 5
Examples:
Summoning Level 25
Possible Boss Levels
10 → 30
Summoning Level 40
Possible Boss Levels
25 → 45
Summoning Level 55
Possible Boss Levels
40 → 60
Lower-level bosses are considerably more common than higher-level bosses within this range.
Every player starts at Summoning Level 5, and this value can only increase.
Increasing your Summoning Level
Only two mechanics can increase your Summoning Level.
Method 1 — Your Zombie Boss is defeated
If one of your spawned Zombie Bosses is defeated at a level higher than your current Summoning Level, your Summoning Level immediately increases to match that boss's level.
It does not matter:
- Who started the rally.
- Who dealt the most damage.
- Who landed the final hit.
- Whether you joined the rally.
As long as your Zombie Boss is defeated, your Summoning Level is updated.
Method 2 — You lead the rally
If you are the rally leader and successfully defeat a Zombie Boss whose level is equal to or higher than your current Summoning Level, your Summoning Level increases by 5 levels.
This bonus can occur up to three times during a single Zombie Invasion event.
Example
Assume your current Summoning Level is 25.
Your Zombie Bosses can spawn between Level 10 and Level 30.
Scenario A
You spawn a Level 30 Zombie Boss.
Another alliance member defeats it.
Result:
- Summoning Level increases from 25 to 30.
- Future Zombie Bosses can spawn between Level 15 and Level 35.
Scenario B
You personally lead a rally against a Level 25 Zombie Boss.
Result:
- Summoning Level increases from 25 to 30.
- Future Zombie Bosses can spawn between Level 15 and Level 35.
Alliance Impact
As players increase their Summoning Level, they naturally begin spawning stronger Zombie Bosses.
Because defeating one of your spawned bosses can permanently increase your Summoning Level, Zombie Boss difficulty tends to increase over time.
Understanding this mechanic helps explain why newer players may eventually begin spawning bosses that are much stronger than those they encountered when they first unlocked the event.
Frequently Asked Questions
Can I lower my Summoning Level?
No.
Once increased, Summoning Level cannot currently be reduced.
Does HQ Level affect Zombie Boss levels?
No.
HQ Level has no effect on Zombie Boss spawning.
Does Commander Power affect Zombie Boss levels?
No.
Commander Power does not influence Zombie Boss levels.
Do stronger heroes increase Zombie Boss levels?
No.
Hero strength has no effect on the bosses you can spawn.
Can I skip multiple Summoning Levels?
Yes.
If one of your spawned Zombie Bosses is defeated at a level higher than your current Summoning Level, your Summoning Level immediately jumps to that boss's level.
Can another player increase my Summoning Level?
Yes.
If another player defeats your spawned Zombie Boss, your Summoning Level will still increase if the required conditions are met.
Can I increase my Summoning Level faster?
Yes.
Leading your own rallies against Zombie Bosses at or above your current Summoning Level grants an additional +5 Summoning Levels, up to three times during each Zombie Invasion event.
Notes
The mechanics described in this guide are based on official responses from the game's customer support together with extensive community testing.
Some players have reported occasional Zombie Boss levels outside the expected spawn range. Whether these are caused by undocumented mechanics, rare exceptions, or inconsistencies within the game is currently unknown.
At the time of writing, the Summoning Level system described above is the most accurate explanation available.
Trade Store
The Zombie Invasion Trade Store allows Courage Medals to be exchanged for various rewards.
Some items become available only after your server reaches specific milestones.
For example, Oil becomes available after entering the Season 3 Pre-Season.
Recommended purchase priority (Free-to-Play)
- Stamina
- Legendary Gold Chest
- Universal Exclusive Weapon Shards
- Drone Parts
- Purple Gold Chest
Tips
- There is no fixed number of zombies required before a Zombie Boss appears. Every defeated zombie has an independent chance to spawn one.
- The game's recommended power value should only be used as a guideline. Rally composition is generally more important than the displayed recommendation.
- Coordinate with your alliance before attacking another alliance's discovered Zombie Boss, as many servers follow additional etiquette beyond the built-in 10-minute protection period.
- If your goal is to increase your Summoning Level efficiently, prioritize leading your own Zombie Boss rallies whenever possible.