HP Gained at Level Up

Rules As Written

When you gain a level, you increase your maximum hit points by rolling the hit die granted by the class you are leveling up and adding your constitution modifier (PHB 15).

House Rule

Roll your hit dice with advantage. If you choose to do this, you may not talk half and must use the highest number rolled.

Rationalisation/Reason for the Rule

No one ever rolls for health anymore - and why would you!?