Can you comp a table? How do you give a discount?

Hi everyone. I'm just wondering how you give a discount to someone. Can anyone help me? I'm only on level 4.

Thanks in advance!

I've never done this. I know that in the later scenarios when you can convince customers to order their favorite dish, you can change the price then. Other than that, I'm not sure how to comp a table or if it's possible! Even though the menu does have that strange line about discounts at the bottom...