# Rules & rollouts in the UI

> Building targeting rules and setting rollout percentages.

Targeting rules and rollouts are set **per environment** on a flag's detail page.
This page covers building them in the UI; for the underlying model, see
[Targeting rules](/docs/concepts/targeting) and
[Percentage rollouts](/docs/concepts/rollouts).

## Building rules

Each environment section has a rule builder. The structure is **groups of
conditions**:

1. **Add a condition** to a group — pick an attribute (e.g. `plan`), an operator
   (e.g. `equals`), and a value (e.g. `enterprise`).
2. **Add more conditions to the same group** to require all of them — conditions
   within a group are **AND**ed.
3. **Add another group** for an alternative — groups are **OR**ed. A user matching
   any group in full gets the enabled value.

This builds the "OR of ANDs" logic described in
[Targeting rules](/docs/concepts/targeting). The attributes you type here are the
keys you'll pass in the SDK's `user` object.

![A flag's Production section: two rule groups combined with OR, and a rollout slider set to 25%](/docs-img/flag-targeting.png "(country equals US AND device equals mobile) OR (plan equals enterprise), with a 25% rollout for everyone else.")

### Attaching a segment

A group can also reference a **segment** — a reusable named audience defined in
the project's **Segments** area. Attach a segment to a group and it's AND-ed in
like any other condition. Edit the segment once and every flag that uses it
updates. Segments are expanded inline when the config publishes, so your SDK only
ever sees plain conditions.

## Setting a rollout

By default a flag has no rollout — when enabled, it serves to everyone who isn't
otherwise targeted. To release gradually, set a **rollout percentage**: a slider
appears once you opt into a rollout. Set it to 10, watch your metrics, then raise
it.

Bucketing is deterministic and stable as you ramp — see
[Percentage rollouts](/docs/concepts/rollouts). Users who match a rule get the
flag regardless of the rollout; the percentage only governs the rest.

## Save to publish

Rules and rollouts follow the same [explicit-save model](/docs/dashboard/flags) as
everything else. Build your targeting, review it, then **Save** — that publishes
one new config for the environment.

## Test before you trust it

Use the **Playground** to check how a flag evaluates for a sample user before you
rely on it — pick a project and environment, enter a user context, and see which
group matched and why. It uses the real SDK evaluator, so it matches what your app
will do.

## Next

- [Rule operators](/docs/reference/operators) — every operator, with examples.
- [Evaluation order](/docs/reference/evaluation-order) — exact precedence.