The golden rule: never uninstall first
Your unlocked roster and campaign progress live in the app's local data. Uninstalling wipes it. To update Arena 2D, install the new APK directly over the old one and everything carries over.
The Arena 2D battle arena homepage always shows the current verified build so you know when an update exists.
Step 1: Download the new build
Get the latest verified file from the APK download page. Check that the version number is actually newer than what you have installed.
Step 2: Install over the old version
Open the new APK and tap install. Android recognizes the matching com.empress.pokemon.arena signature and updates in place. Your fighters, progress, and settings survive.
Step 3: Verify after updating
Launch the game, check your roster is intact, and play one training match to confirm the new build runs. If anything looks wrong, the Pokemon Arena 2D install fixes apply to updates too. The homepage always shows the current build so you know when an update exists.
