After you train a new rank, check your bars: mana users may still be casting the old one.
- New ability ranks are bought from the class trainer.
- For mana users, including melee classes with mana abilities, the new rank may not replace the old one on the action bar.
- Rogues and Warriors update automatically. Other classes can keep a lower rank for a lower cost and less damage.
- The spellbook hides lower ranks until you hover the down arrow at the top right and choose show all ranks.
Unconfirmed which spells are worth keeping at a lower rank.
Source Wowhead, 22 Sep 2026.