The format
Twice per cycle (Tuesday to Thursday windows in weeks 2 and 4), 20 waves of AI Vikings attack your alliance's cities. Each wave you defend scores by kills: clear the whole attacking force and you bank close to that wave's full value, and you need to kill at least 50% of a wave to count as defending it. Lose twice and the Vikings stop attacking your city for the rest of the event, which caps your defensive score but, and this is the part most players miss, doesn't stop you from scoring at all.
The wave table
| Waves | Who gets attacked |
|---|---|
| 1–6, 8–9, 11–13, 15–16, 18–19 | All registered members |
| 7, 14, 17 | Online members only |
| 10, 20 | Alliance HQ only |
Two consequences. Being online is worth real points, because three waves only exist for players who are logged in. And after waves 9 and 19 finish, recall one strong march with your best defensive heroes and reinforce the HQ, because waves 10 and 20 hit nothing else. An HQ that shrugs off wave 20 is the difference between a full-clear event and a stalled one for the whole alliance.
Reinforcement points: the real leaderboard
Kills your troops make while garrisoned in an ally's city pay you separate reinforcement points, and they don't reduce the host's score by one point. Both of you get paid for the same dead Vikings. That single rule turns the event from a defense check into a deployment race: the top scorers spread marches across roughly six online members' cities and farm every wave hitting any of them, while a player who sits home only scores their own waves.
- Reinforce online members first; they eat the online-only waves 7, 14, and 17 that offline cities never see.
- Send infantry-and-cavalry-heavy marches; they do the killing in city defense.
- Lead each reinforcement with your rally-joiner heroes: the same first-skill math from the Bear Trap rankings applies, since one lead hero's expedition skill rides along.
- If your city is out after two losses, go full deployment: every march you own belongs in someone else's city for the remaining waves.
Setting up your own city
Scoring is about clear rate: killing 100% of a wave banks nearly its full value, so the setup goal is a city that clears, not one that merely survives. Keep your defense stacked with your best garrison heroes (the garrison rankings transfer directly), pick the highest difficulty your wall can clear at 100% rather than a higher one it clears at 60%, and watch the 50% threshold: a difficulty that drops you below it costs the wave entirely, and two of those end your defensive event.
FAQ
Does reinforcing steal points from my alliance mate?
No. Reinforcement kills pay you a separate score and the host keeps theirs in full, so a city packed with allied garrisons pays everyone in it at once.
Should I pick the highest difficulty?
Only if you clear it. Full clears bank nearly the wave's whole value, so a difficulty you clear completely beats a harder one you survive at 55%, and one you'd fail below 50% is strictly worse than stepping down.
What happens when I lose two waves?
Vikings stop attacking your city for the rest of the event. Your defensive scoring ends, but reinforcement scoring doesn't, so redeploy everything to allies and keep earning.