---
title: "GPT-5.6 Luna plays Detroit 1972 (seed 1) | Micropolis run | Evals by Jetty"
url: https://evaljetty.com/micropolis/runs/gpt56luna-detroit-s1.html
description: "GPT-5.6 Luna as mayor in Micropolis, Detroit 1972: crime: lost, city score 547. Timelapse, charts, every decision and the run's evaluation."
updated: 2026-09-28
publisher: Jetty (https://jetty.io)
---

02 — Run · Round 1 · Detroit 1972: crime · gpt56luna-detroit-s1

# GPT-5.6 Luna plays Detroit 1972

Detroit's crime is out of control in 1972. Bring average crime under 60 in 10 years, without emptying the city. Ended Jan 1982: lost, city score 547.

[Decision log](https://evaljetty.com/micropolis/runs/gpt56luna-detroit-s1/decisions.jsonl)[City stats (CSV)](https://evaljetty.com/micropolis/runs/gpt56luna-detroit-s1/series.csv)[Save file (.cty)](https://evaljetty.com/micropolis/runs/gpt56luna-detroit-s1/city.cty)[Final map (PNG)](https://evaljetty.com/micropolis/runs/gpt56luna-detroit-s1/final_map.png)[Runtime config](https://evaljetty.com/micropolis/runs/gpt56luna-detroit-s1/runtime_config.json)[Validation report](https://evaljetty.com/micropolis/runs/gpt56luna-detroit-s1/validation_report.json)

GOAL MISSED seed 1

GPT-5.6 Luna

openai/gpt-5.6-luna

LOST: Average crime 24 (goal < 60), population 7,400 (floor 25,000); engine verdict: won

Population (start → end)76,160 → 7,400
Peak population76,160City score (start → end)285 → 547
Funds at the end$1Crime / pollution / traffic24 / 45 / 0
Zones R / C / I160 / 67 / 94
Power plants (coal / nuclear)2 / 3Police / fire stations16 / 7
Turns (model / failed)40 (40 / 0)
Actions applied / rejected188 / 40
Mean turn latency7.0sModel cost$0.084Wall clock4.8 min
Jetty run IDfde1c078

## The city over time

### Population

People, after every turn

### Funds

Treasury, after every turn

### City score

0–1000, re-evaluated each January

Table view

| Turn | Date | Population | Funds | City score | Crime | Pollution |
| --- | --- | --- | --- | --- | --- | --- |
| 0 | Jan 1972 | 76,160 | $20,000 | 285 | 92 | 67 |
| 1 | Apr 1972 | 73,380 | $18,344 | 539 | 92 | 67 |
| 2 | Jul 1972 | 70,720 | $16,598 | 539 | 107 | 64 |
| 3 | Oct 1972 | 64,740 | $15,723 | 539 | 107 | 60 |
| 4 | Jan 1973 | 59,880 | $12,273 | 462 | 107 | 60 |
| 5 | Apr 1973 | 54,900 | $10,271 | 462 | 82 | 54 |
| 6 | Jul 1973 | 50,000 | $10,209 | 462 | 77 | 55 |
| 7 | Oct 1973 | 47,140 | $9,174 | 462 | 77 | 55 |
| 8 | Jan 1974 | 43,700 | $5,998 | 397 | 65 | 54 |
| 9 | Apr 1974 | 37,680 | $5,483 | 397 | 54 | 48 |
| 10 | Jul 1974 | 33,100 | $5,478 | 397 | 54 | 48 |
| 11 | Oct 1974 | 29,140 | $5,400 | 397 | 48 | 48 |
| 12 | Jan 1975 | 25,640 | $3,503 | 333 | 43 | 47 |
| 13 | Apr 1975 | 23,360 | $2,999 | 333 | 43 | 49 |
| 14 | Jul 1975 | 21,240 | $2,999 | 333 | 36 | 49 |
| 15 | Oct 1975 | 18,740 | $2,871 | 333 | 33 | 49 |
| 16 | Jan 1976 | 17,020 | $0 | 325 | 33 | 46 |
| 17 | Apr 1976 | 15,620 | $0 | 325 | 30 | 47 |
| 18 | Jul 1976 | 14,120 | $0 | 325 | 29 | 47 |
| 19 | Oct 1976 | 12,720 | $0 | 325 | 29 | 45 |
| 20 | Jan 1977 | 12,980 | $11 | 412 | 27 | 44 |
| 21 | Apr 1977 | 12,040 | $11 | 412 | 27 | 44 |
| 22 | Jul 1977 | 10,020 | $11 | 412 | 27 | 47 |
| 23 | Oct 1977 | 8,780 | $11 | 412 | 25 | 46 |
| 24 | Jan 1978 | 7,880 | $193 | 333 | 23 | 46 |
| 25 | Apr 1978 | 8,240 | $13 | 333 | 23 | 46 |
| 26 | Jul 1978 | 11,040 | $13 | 333 | 25 | 46 |
| 27 | Oct 1978 | 10,360 | $13 | 333 | 25 | 50 |
| 28 | Jan 1979 | 8,080 | $216 | 434 | 25 | 50 |
| 29 | Apr 1979 | 7,040 | $12 | 434 | 26 | 53 |
| 30 | Jul 1979 | 6,000 | $12 | 434 | 24 | 52 |
| 31 | Oct 1979 | 5,500 | $12 | 434 | 24 | 52 |
| 32 | Jan 1980 | 7,880 | $12 | 606 | 22 | 56 |
| 33 | Apr 1980 | 12,500 | $2 | 606 | 22 | 48 |
| 34 | Jul 1980 | 12,420 | $2 | 606 | 22 | 51 |
| 35 | Oct 1980 | 11,520 | $2 | 606 | 28 | 51 |
| 36 | Jan 1981 | 9,860 | $315 | 687 | 27 | 48 |
| 37 | Apr 1981 | 8,560 | $6 | 687 | 27 | 46 |
| 38 | Jul 1981 | 8,220 | $1 | 687 | 26 | 46 |
| 39 | Oct 1981 | 7,740 | $1 | 687 | 24 | 46 |
| 40 | Jan 1982 | 7,240 | $1 | 547 | 24 | 45 |

## Final map

[![Final city map: GPT-5.6 Luna on Detroit 1972: crime](https://evaljetty.com/micropolis/media/gpt56luna-detroit-s1-map.jpg)](https://evaljetty.com/micropolis/runs/gpt56luna-detroit-s1/final_map.png)

## Evaluation

failchecks **9/10** verdict: valid run (code checks and checklist) and task goal met (judge)

| Status | Kind | Check | Detail |
| --- | --- | --- | --- |
| pass | step | environment | Environment check (snapshot, engine, key) |
| pass | step | launch | Launch run-city as a detached process |
| pass | step | supervise | Supervise in the foreground until run-city exits |
| pass | step | render | Timelapse video rendered |
| pass | step | notes | Append Notes to summary.md |
| pass | code\_check | outputs-exist | all present |
| pass | code\_check | sim-reached-deadline | ended Jan 1982 after 40 turns; scenario verdict True |
| pass | code\_check | decisions-logged | 40 rows for 40 turns |
| pass | code\_check | llm-turns-valid | 0/40 model turns failed |
| pass | code\_check | video-decodes | duration 36.9s |
| pass | code\_check | limits-respected | 4.8 wall-minutes (model budget 45.0 min) |
| fail | judge | scenario-goal | LOST: Average crime 24 (goal < 60), population 7,400 (floor 25,000); engine verdict: won (score 0 / threshold 1) |
| pass | checklist | notes-explain-outcome | Notes section added citing model thoughts from turns 1, 28, and 40 explaining the crime-vs-population trade-off |
| pass | checklist | player-matches-request | result.json confirms player=gpt56luna model=openai/gpt-5.6-luna task=detroit seed=1 matching requested parameters |
| pass | checklist | no-silent-outage | run.log shows 0 failed model turns across all 40 turns with continuous per-turn logging |

## Decision timeline

What the mayor thought and did each turn. Click a turn to jump the timelapse there.

---
Source: https://evaljetty.com/micropolis/runs/gpt56luna-detroit-s1.html · Evals by Jetty · Run your own evals: https://jetty.io/?utm_source=evaljetty&utm_medium=llms