How to get an S in Serum Shot
Updated September 28, 2026. Figures come from the live game.
The short answer
A needle sweeps a gauge; tap while it's in the green band, as close to the band's centre as you can. An S binds 5 zombies in 1 minute instead of 3 in 3 minutes. Binding ten batches at once plays one Serum Shot, and its grade counts for all ten. Red decoy bands from level 16 score nothing.
Why Serum Shot matters most
| Grade | Zombies per batch | Bind time |
|---|---|---|
| S | 5 | 1 minute |
| A | 4 | 2 minutes |
| B or C | 3 | 3 minutes |
Every batch costs the same 6 serum and 20 biomass whatever the grade, so an S gets you 67 % more zombies for the same serum.
How it's scored
- Each shot is worth an equal share of 1,000.
- Inside the band, the closer to the band's centre, the more of that share you keep. Outside the band, nothing.
- Tapping within 120 ms of a shot starting scores nothing: wait for the needle to move.
- A tap on a red decoy band scores nothing.
How it gets harder
| Skill level | Shots | Band | Tricks |
|---|---|---|---|
| 1 | 3 | Widest (22 % of the gauge) | — |
| 8 | More | Narrower | The band moves between shots |
| 16 | More | Narrower | One red decoy band |
| 24 | More | Narrower | Two decoy bands |
| 30 | 8 | 6 % of the gauge | Fastest needle |
Questions players ask
Does a better Serum Shot grade cost more serum?
No. Every batch costs 6 serum and 20 biomass. The grade only changes how many zombies you get and how fast.
Where can I practise Serum Shot?
In the Training Yard, from the Train button on the village. Three runs a day are paid in serum and biomass.