Tune one mcMMO activity reward without resetting existing levels

A single activity can reward too much or too little XP while the rest of the skill feels right. Change its future reward independently of existing player progression.
Check the installed content
mcMMO progress belongs to player data, while its configuration controls future skill behaviour. Preserve both before changing progression rules. Match the installed release when checking permissions and configuration; current configuration references identify changes that require a full server restart.
Work through the change
Choose the exact skill source and write down the intended new reward. Save experience.yml and a completed player-data backup before editing progression configuration.
Locate the source entry in the reference for the installed release. Distinguish the activity reward from a global multiplier so the change stays limited to the intended behaviour.
Apply a small staging adjustment and perform a normal restart as required by the documentation. Compare the same activity with equivalent tools and account bonuses before and after.
Test another activity within the same skill and one unrelated skill. Confirm their baseline rewards remain unchanged and inspect a test player existing level after the restart.
Verify the result
The selected activity should award the intended new amount while other sources and stored levels remain intact. Record the measured difference so players can understand the balance change.
If the result differs
If all activities change, inspect the multiplier or enclosing section edited. If nothing changes, confirm the server loaded the intended file and source rather than repeatedly raising the configured value.
Keep a recovery path
Restore the saved configuration if the balance is unsuitable. Do not roll back the player database for a reward-rate change unless a separate reviewed recovery requires it; configuration and earned progression have different recovery implications.
References and related help
Check the maintainer reference: mcMMO documentation.
Before changing live data, read how to keep a completed recovery copy. For startup errors, use the log collection guide.