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What Kills an AI Survivor in DayZ? A Rerun Devlog
In short: Between 30 September and 5 October, deaths among Rerun's AI survivors fell from 1.9 to 0.17 per 100 survivor-hours, and the typical survivor who died had lived 29 hours instead of one. Most early deaths were illness and starvation.
Rerun's AI survivors live by the same needs as players: food, water, warmth and blood. That also means they can die of the same things. Here is what killed them in the first week of October, and what we changed.
The numbers
Per day, Amsterdam time. "Survivor-hours" is how many hours all survivors were alive and on the map together; we use it because the number of survivors grew from 20 to 25 during the week.
| Day | Deaths | Per 100 survivor-hours | Median life at death | Causes |
|---|---|---|---|---|
| 30 Sep | 2 | 0.42 | 1.1 h | starvation, illness |
| 1 Oct | 6 | 1.27 | 1.2 h | 4 starvation, 2 illness |
| 2 Oct | 9 | 1.91 | 1.1 h | 5 illness, 2 starvation, 2 infected |
| 3 Oct | 5 | 1.06 | 2.1 h | 3 unknown, toxic gas, illness |
| 4 Oct | 1 | 0.20 | 19.4 h | toxic gas |
| 5 Oct | 1 | 0.17 | 29.5 h | a fall |
Over these six days, 24 survivors died: 9 of illness, 7 of starvation, 3 of unknown causes, 2 in toxic gas, 2 to infected and 1 from a fall. None of the known causes was another survivor or a player.
Why did they die so young at first?
Early in the week, a survivor that died had usually lived about an hour. Two things made that worse than it sounds. A server restart every four hours gave every survivor a fresh body, so nobody grew old. And a survivor that opened a can without being very hungry often walked away from it, leaving food behind that it could have used later.
What changed?
We shipped more than thirty small updates that week. Three of them stand out:
- Finishing a meal (3 October). A survivor that isn't hungry now finishes the food it already opened while its stomach has room, instead of leaving it.
- Living through a restart (3 and 4 October). A survivor now keeps its body, blood, backpack and identity across the four-hourly restart. That is why the longest-living survivor has now made it past 60 hours.
- Staying out of toxic gas (4 October). Survivors keep 30 metres away from gas zones, don't loot or travel through them, and walk out if they end up inside one.
We can't pin every saved life on one update: several changes landed on the same days, and one or two deaths a day is a small number. But the direction is clear, and it has held since.
What's next?
On 6 October the server went from 25 to 30 survivors, and on 7 October to 60. That evening a calmer first contact went live too: a survivor now leaves a player alone until the player threatens it. Next we'll see whether 60 survivors die as rarely as 30 did. Follow along in the daily log, which tells every day on Chernarus in a few lines.
How we measured
All numbers come from the server's own logs, which our exporter reads every few minutes; the same numbers feed the stats page. A death counts on the day it happens, in Amsterdam time. "Median life at death" is the middle value of how long the survivors who died that day had lived. Days are complete 24-hour days on the server.
By Lon · published 6 October 2026 · updated 7 October 2026