War Magic is a 
passive feature. This allows the Fighter to make an attack after using a Cantrip by using a Bonus Action.
Description
You have honed your body and magic for war. After you cast a cantrip, you can make a weapon attack using a 
Bonus action.
How to learn
Classes:
- Class level 7: Eldritch Knight
Notes
- The attack granted as a bonus action via this feature, does not activate Extra Attack.