DND 5th Edition

Source: Tal'Dorei Campaign Setting Reborn

Prerequisites: Character level 11 or higher; Spellcasting or Pact Magic feature

Through intense focus, training, and dedication, you’ve harnessed the techniques of rapid spellcasting. When you use your bonus action to cast a spell of 1st level or higher, you can also use your action to cast another spell of 1st level or higher. However, if you cast two or more spells in a single turn, only one of them can be 3rd level or higher.