Proficient memory

You may prepare additional spells for each day equal to your proficiency bonus.

You may as an Action exchange one prepared spell for a spell you have not prepared, but know. The spell must be of the same level or lower than the one discarded.

You may do this twice per Long Rest

 If the discarded spell has been cast and requires concentration, the spell ends immediately.

 This ability is regained after a long rest.

Classes: Cleric, Druid, Wizard, Ranger, Paladin