Undead Siege: Complete Guide
Alliance defense against infected waves: the 300,000 clue bar, difficulty levels from 2.4M to 24.5M Enemy Might, the hidden multi-squad mechanic that kills 9.5M players, and full reward tables.
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🗓 Updated: 2026-09-03
Undead Siege is the alliance defense event: your whole alliance stands against waves of infected, with heroes on the wall doing the fighting. Two rules define it before anything else: shields do not work, and it is not a points event — the goal is to defend as many waves as possible.
This guide covers how sieges unlock, the difficulty ladder, the hidden multi-squad mechanic that wipes underprepared alliances, rewards, and the top seven mistakes.
How a Siege Unlocks
Sieges are not on a timer — your alliance triggers them (the event becomes available to Alliances 2 weeks after server launch — July 9, 2026 update):
- Fill the 300,000 Clue Points bar.
- An R4 or R5 finds the hidden Death Prison on the map.
- That leader starts the siege and chooses the difficulty.
- The siege begins roughly 4 hours after the click — use that gap to get every member’s heroes on the wall.
Clue points come from normal daily play:
- Attacking Rebels and the Blight Legion
- Killing Wandering Blights
- Gathering resources on tiles
- Helping allies (help-build and help-research taps)
- Running Alliance Excavation
- Completing Falcon Quests
An active alliance fills the bar through ordinary play; the bar is not the bottleneck, readiness is.
Difficulty Levels
| Difficulty | Enemy Might | Territory |
|---|---|---|
| Level 1 | 2.4M | Territory 13 |
| Level 6 | ~3 squads per wave | — |
| Level 10 | 24.5M | Territory 27 |
The ladder scales continuously from 2.4M Enemy Might at Level 1 up to 24.5M at Level 10, with territory requirements rising from 13 to 27. Higher difficulty levels also unlock Enemy Mutations — preview the mutations before committing to a difficulty, because a mutation that counters your defense comp is worth millions of Enemy Might.
The Hidden Multi-Squad Mechanic
This is the part of the event the difficulty screen does not tell you, and it is the difference between surviving 20 waves and collapsing at 17:
- The siege sends 2 or more squads at the stated might. Stated 8M means you fight two squads of 8M — effectively double the number on the button.
- At wave 17 of an 8M difficulty, the actual strength is roughly 7.3M x 2.
- At difficulty 6 and above, waves send 3 squads.
- Squad HP persists between waves. Your tank starts the next fight at whatever HP it ended the last one — and your squad 1 must survive back-to-back fights with no heal in between.
A 9.5M player died at wave 17 of an 8M difficulty — worn down by consecutive fights with persistent HP. The stated might is not the fight.
Rewards
Personal Milestones
Each player faces 20 solo waves, with milestones at waves 1, 4, 8, 10, 13, 16 and 20 — tokens, upgrades and chests. If your city falls it will not be attacked again, but your personal rewards stop there: dying at wave 12 of 20 forfeits every milestone after it.
Alliance Milestones
| Alliance total waves | Rewards |
|---|---|
| 50 | Hero XP, materials, medals |
| 100 | Hero XP, materials, medals |
| 150 | Hero XP, materials, medals |
| 200 | Hero XP, materials, medals |
| 250 | Hero XP, materials, medals |
| 300 | Hero XP, materials, medals |
Two rules around the alliance total:
- Membership over 48 hours is required to receive alliance rewards — new joins don’t collect.
- Reinforcing other members doesn’t double your personal rewards — it raises the alliance total. Do it anyway: the alliance milestones are the big payout.
The all-time record stands at 1,193 waves in a single siege.
Deployment: Squads and Reinforcing
- Your strongest squad goes on your own wall. That squad carries your 20 personal waves.
- The rest of your squads reinforce other members — reinforcing raises the alliance total, which is where the shared rewards live.
- Reinforcements land at the member’s wall and fight the incoming waves with them — send them before the waves hit, not after the notification.
The Top 7 Mistakes
- Heroes not on the wall — the biggest killer. Heroes on the wall are the event; a wall with no heroes is a city waiting to fall.
- Ignoring wall defense — there is no auto-defend in this event. Whatever you preset is what fights.
- Starting without 100% clue completion — a rushed start wastes the 4-hour warning window.
- Underestimating mutations — always read the mutation preview before choosing the difficulty.
- Not reinforcing members — the alliance milestones need bodies on every wall, not just your own.
- Starting with partial squads — a half-empty wall squad is a dead wall squad.
- Logging off without preset defense — offline defense works, but only if it was pre-set. Set it, then sleep.
Run the event with those seven fixed and your alliance defends near its ceiling. Hero setup for the wall and squad composition are covered in the Heroes guide.
🎥Video guides
Curated video guides and strategic breakdowns from community creators
Undead Siege Complete Event Guide
Top 7 Undead Siege Mistakes to Avoid
Undead Siege Gameplay Tips & Reinforcement Mechanics
Search YouTube for this topic: «Undead Siege»
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