Events

All events fire synchronously on the player's owner thread, and post events do not guarantee that asynchronous persistence has already been written to disk

Event	Timing	Cancellable	Mutable field	Cancellation/effect
PlayerExpGainEvent	Before experience is written	Yes	amount	Cancellation or amount <= 0 prevents the gain; replacement amount is quota-checked again
PlayerPreLevelUpEvent	After non-mutating checks, immediately before level-up mutation	Yes	None	Prevents the level-up mutation
PlayerLevelUpEvent	After a successful level gain	No	None	Reports old/new level and cause
PlayerLevelChangeEvent	After a level-changing operation commits	No	None	Reports old/new level, operation type, and direction
PlayerMaxLevelReachedEvent	When the maximum level is reached	No	None	Reports type, max level, and cause

Post events are informational and cannot cancel persistence or revert the committed in-memory change. Asynchronous catalog loading itself does not publish these mutation events