> ## Documentation Index
> Fetch the complete documentation index at: https://docs.getnovaplan.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Scenarios

> Test what-ifs against a base plan without disturbing it.

A scenario layers a set of assumption changes on top of a budget version so you can ask "what if" and compare the answer against your base, side by side. The base plan is never touched, so you can explore freely and keep only the versions worth keeping.

## What You Can Change

* Hiring pace and timing for headcount.
* Growth, churn, and renewal rates for revenue.
* Specific assumptions on specific departments, streams, or periods.

A scenario starts identical to its base. Only the assumptions you change are different; everything else inherits, so the comparison shows the effect of your change alone.

## How to Use It

<Steps>
  <Step title="Create a scenario">
    Branch from a base version. The scenario starts as an exact copy.
  </Step>

  <Step title="Adjust assumptions">
    Change only what you want to test. You can ask Nova to draft the assumption changes from a plain-language description, then accept or refine them.
  </Step>

  <Step title="Run the forecast">
    Re-run so the engine projects the scenario with your changes applied.
  </Step>

  <Step title="Compare">
    View the scenario against the base in the [Comparison Center](/reporting/comparison-center) to see the delta on every line.
  </Step>
</Steps>

## Scenarios vs Mid-Year Updates vs Rules

| Tool                                        | Use it to                                                            |
| ------------------------------------------- | -------------------------------------------------------------------- |
| **Scenario**                                | Test a what-if against your base without committing to it            |
| **[Mid-year update](/planning/reforecast)** | Refresh the live outlook for the rest of the year as actuals come in |
| **[Budget Rules](/planning/budget-rules)**  | Express how a number should allocate or derive, in any version       |

<Tip>
  Scenarios are non-destructive. Because the base is frozen relative to the scenario, you can spin up several what-ifs from the same base and compare them all against it.
</Tip>

## Common Questions

<AccordionGroup>
  <Accordion title="Will editing a scenario change my base plan?">
    No. A scenario is a separate layer. Your base version stays exactly as it was, which is what makes the side-by-side comparison meaningful.
  </Accordion>

  <Accordion title="How do I see the impact of a scenario?">
    Open the [Comparison Center](/reporting/comparison-center) and put the scenario against its base. Every line shows the dollar and percent delta.
  </Accordion>

  <Accordion title="Can Nova build a scenario for me?">
    Yes. Describe the what-if in plain language ("push all engineering hires to Q3, raise churn to 8 percent") and Nova drafts the assumption changes for you to review before applying.
  </Accordion>

  <Accordion title="What if I want to make a scenario the new plan?">
    Promote it: once a what-if is the direction you want, you keep it as a version and compare future work against it. The original base remains available for history.
  </Accordion>
</AccordionGroup>

## If the Numbers Look Off

* The scenario looks identical to the base: you have not changed an assumption that the engine reads, or you have not re-run the forecast since changing it.
* A change had no effect on a line: confirm the assumption you edited is scoped to the department, stream, or period that line belongs to.