1. A staged rollout releases an app update to only a percentage of your production users (e.g. 1%, 5%, 10%, 25%, 50%, 100%) and you increase the percentage over time as you gain confidence; it applies to app updates only, not first-time publications.
2. In Play Console, select "Staged rollout" when creating a production release and set the initial percentage - the update reaches a randomly selected group of that size, and users are not notified that they received a staged version.
3. You can limit a staged rollout to specific countries - the update is then delivered only to users whose Google Play accounts are located there, which is useful for regional launches.
4. Monitor Android vitals (crash rate, ANR rate) and new user reviews after each step; only increase the percentage when the new version's crash/ANR metrics are stable and at or below the previous version's baseline.
5. You can halt a rollout at any time - users who already received the update keep it, but no new users get it; a halted rollout can be resumed at the same percentage later.
6. Rollout percentages cannot be decreased: if the update performs worse than expected, halt instead of lowering the number, and ship a fixed release to reach remaining users - do not rely on "rollback" of the current release.
7. Best practice: start small (1-5%), wait 12-24 hours per stage, keep a hotfix plan ready, and avoid pushing a major update to 100% on a Friday with no support coverage; combine with Managed Publishing for manual confirmation before each step.