Hammer Guide
The medical hammer tests survivor reflexes to detect neurological symptoms of infection. Learn to identify different reflex responses and know when a survivor is safe or infected.
Tool Quick Info
Visual Cues Before Testing
Survivors with hammer-detectable symptoms have a distinctive look: OPEN MOUTH and SLACK JAW. If a survivor's mouth is closed normally, they likely have normal reflexes and you can skip the hammer test entirely.
Danger Warning
Hyperaggressive survivors will ATTACK you when you hit them with the hammer! Keep your distance when testing. If a survivor has BOTH hyperaggression AND crossed reflex, they will swing at you with the OPPOSITE arm - extremely dangerous!
How to Use the Hammer
Check for Visual Cues First
Look at the survivor's face - survivors with reflex symptoms have an OPEN MOUTH and SLACK JAW. If their mouth is closed, they likely have normal reflexes and you can skip this tool.
Equip the Hammer
Pick up the medical hammer from the medical station or your inventory. Position yourself close to but not touching the survivor.
Aim for the Forearm
Target the survivor's forearm near the hand for the most visible reaction. This area produces the clearest reflex response.
Swing Multiple Times
Take several swings at the forearm. A normal reflex will cause the arm to swing about a foot away. Watch carefully for the type of response.
Note the Response
Normal: Arm swings a foot away. Absent: Arm barely moves (tiny jerk). Hyperaggressive: Survivor swings at you. Crossed: Opposite arm reacts.
Reflex Response Patterns
Normal Reflex (No Symptom)
Response
Arm swings about a foot away from the hit
Action
Do not mark anything
The arm swings naturally in response to the hit. This is normal healthy behavior - don't mark any symptom.
Absent Reflex
Response
Arm barely moves - tiny jerk but no swing
Action
Allow into Living Block
The arm jerks slightly (about an inch) but never swings no matter how many times you hit. The survivor has nerve damage but is not infected.
Hyperaggressive Reflex
Response
Survivor swings at you with clawed hand
Action
Send to Quarantine
When hit, the survivor attacks you with the same arm you hit. WARNING: This attack can damage you if you're too close! Keep your distance.
Crossed Reflex
Response
Opposite arm reacts to the hit
Action
Liquidate Immediately
When you hit the right arm, the LEFT arm swings (or vice versa). This neurological crossover indicates definite infection.
Symptoms Detected by Hammer
| Symptom | Response | Danger Level | Action |
|---|---|---|---|
| Absent Reflex | Arm barely moves - tiny jerk but no swing | Green - Safe | Allow into Living Block |
| Hyperaggressive Reflex | Survivor swings at you with clawed hand | Orange - Quarantine | Send to Quarantine |
| Crossed Reflex | Opposite arm reacts to the hit | Red - Infected | Liquidate Immediately |
Pro Tips
Common Mistakes to Avoid
Testing survivors without open mouth/slack jaw
✓ Only test survivors who show these facial cues - others have normal reflexes
Marking the bruise from hitting as a symptom
✓ The small bruise left by the hammer is NOT a symptom - ignore it
Standing too close when testing
✓ Keep distance - hyperaggressive survivors will attack and damage you
Only hitting once and assuming absent reflex
✓ Hit MULTIPLE times - normal reflexes sometimes need a few hits to trigger
Confusing absent (no swing) with normal (swing)
✓ Absent = tiny jerk only. Normal = arm swings about a foot. They're very different