Stamina, Radar & Zombie Invasion
Getting the most from every point of stamina: radar stacking, Doom Walker rallies, and finding bosses in Zombie Invasion.
Stamina in one minute
- Regenerates 1 every 5 minutes, only while you're under 120.
- Two free 50-stamina claims a day. Don't miss them.
- The VIP Store sells a cheap weekly stamina bundle. Regular refills get pricier every time.
| Activity | Stamina |
|---|---|
| World map zombie | 10 |
| Invading zombie (Zombie Invasion) | 10 |
| Launch a boss / Doom Walker rally | 20 |
| Join someone else's rally | Usually free |
| Survivor, resource and treasure radar tasks | 0 |
Spend it during an Arms Race Drone Boost phase so it scores there too (see Alliance Duel & Arms Race).
Radar missions
- Radar refreshes every 6 hours with new missions, and storage holds a few dozen.
- Don't let it fill up. The refresh timer stops when storage is full.
- Stacking: complete missions but leave the rewards unclaimed, then claim them on Alliance Duel days 1, 3 and 5 (Monday, Wednesday and Friday), when radar scores.
Doom Elite and Doom Walker
- These are rally bosses. Launching costs 20 stamina, joining is usually free.
- Rewards include resources, hero EXP, drone materials and alliance gifts. Kills also give big Zombie Siege clue points.
- Doomsday (about every two weeks, on Sunday) fills the map with Doom Walkers that respawn every few hours and can attack bases through shields.
- Every squad in a Doom Walker rally must be strong enough for its level, or the whole rally fails. If it's too weak, cancel it.
Zombie Invasion (Golden Zombies)
Runs for 3 days about every two weeks, usually midweek.
- Invading zombies spawn at the top of every hour, and the first 15 minutes are busiest.
- Each kill (10 stamina) gives Courage Medals, resources and a chance to reveal a boss.
- Bosses are rally-only. Your alliance gets a short head start on bosses you find, and the finder gets a reward when it dies, even if someone else kills it. So hunt for bosses first, then rally.
- Boss level scales with your best boss kill, and that carries over to future events.
Courage Medal store highlights
| Item | Notes |
|---|---|
| Universal Exclusive Weapon Shards | Usually the best buy |
| Hero Recruitment Tickets | Great value |
| Drone Parts | Good for drone milestones |
| Stamina | A few per event |
Medals carry over between events, but the store is only open while the event runs.
Sources
Compiled from community guides (last checked October 2026). Several are run by top-up shops, and numbers change with updates and differ by server, so double-check anything important in game.