# Experiments (/docs/experiments)

An experiment tests whether a game change moves a metric: a shorter tutorial, a cheaper starter pack, a new map. Results are measured in **game metrics** RoChart computes from the events every game sends: **D1 and D7 retention**, **playtime**, **sessions**, **Robux** and **payer conversion** per player. You can also use your own events. Describe what you want to test, review the plan RoChart drafts, and read the variant in your server code with `RoChart.getFlag`. Once it's live, results update continuously and tell you:

- the **chance each variant is best**;
- the **lift** over control, with a range it very likely falls in;
- a **verdict**: winner, keep control, inconclusive or needs more data;
- whether the **split looks healthy**, **how much longer** to run, and a one-line **recommendation**;
- the same numbers **per cohort**, such as new players vs power players.

You can check results as often as you like. Looking early doesn't invalidate them.

```text title="What you and your agent read"
Experiment "Shorter tutorial" (running). Exposures: control 1475, test 1525.
Primary: D1 retention — control: 30.8% (n=1402); test: 39.1% (n=1449) lift +26.9% [15.0%, 39.8%], P(beats control) 100.0%. Verdict: winner (test).
Secondary: Playtime per player — control: 41.2 min (n=1475); test: 44.0 min (n=1525) lift +6.8% [-1.9%, 16.1%], P(beats control) 93.4%. Verdict: inconclusive.
Segment "Mobile players": D1 retention — … lift +61.2% [27.5%, 102.8%], P(beats control) 100.0%. Verdict: winner (test).
Recommendation: Ship "test": it is the best variant with 100.0% probability.
```

## Lifecycle [#lifecycle]

| Status | What happens |
| --- | --- |
| **Draft** | The experiment and its flag exist, but the flag is off, so nothing changes for players. |
| **Running** | Launch turns the flag on. Exposures and metrics count from here. |
| **Stopped** | No new players enter. Players already in keep counting until their metric window closes. |
| **Concluded** | The decision is recorded: the winner, the reason, and who decided. Optionally the winner is rolled out to everyone. |

Every step shows up in the activity log with the person or agent who took it. Experiments need the [Feature flags](/docs/feature-flags) product.

<Cards>
  <Card icon="plus" title="Create an experiment" href="/docs/experiments/create">
    Describe it, review the plan, put the variant in your code.
  </Card>
  <Card icon="star" title="Read results" href="/docs/experiments/results">
    Verdicts, lift, segments and concluding.
  </Card>
</Cards>