Ok, so here's the deal. For some reason it seems to be a common belief that when you get a discounted meal this also means that you get a discount on your tip. This is most definitely not effing true. Just because you got 25% off your entree doesn't mean I brought you 25% less food. Or filled up your drink 25% less times. Or looked and acted 25% less like a hot ass Hooters Girl. You see even if you food was discounted it doesn't mean you get to use said discount against your tip.
I hate this the most when people use Lunch Punch Cards. Hooters has this sweet thing they do during the weekdays and basically you pay for seven meals and your eighth is free. As you can imagine this can be a pretty good way to bring people in during the week. And I'm all for bringing people into the restaurant. What I'm not for is when people get to that coveted free meal and they totally screw me.
For example, today we had two gentlemen who each had full Lunch Punch Cards. Yay, free shit! Good for you, dudes. They had a couple burgers with extra toppings and took full advantage of the whole free refill thing. Their initial bill was just over $20. But of course they had their sweet Lunch Punch Cards. So when all was said and done all they had to pay for was two Diet Cokes - a whopping $4.98. So do you think they left the $4.00 they should have? Of course not. That would make sense. Instead they left me a whole dollar. Because that is 20% on $4.98 after all. Hell that's even a little extra for me to go crazy with. My bank account adores you.
For the record, please tip on the original amount of your bill. Even if your whole meal is free. Actually, if your whole meal is free you could probably stand to give me more than 20% of the original but whatever. All I'm saying is appreciate your server enough to tip them the correct way no matter how much of a deal you're getting on dinner. Trust me, you're still getting a deal. And I effing know deals.