Be careful out there! If you’re going to go all wild and radical like that, you’ve got to expect there might be some consequences! 
This thread desperately needs a poll so the OP can made a fully informed decision.
And another can of worms – with or without the alcohol cost? Some people do it on food only.
Yes, and those people are called cheap bastards.
There’s a simple formula to use in confusing cases. Take the post-discount price. Double the sales tax and add that in again, if there’s no sales tax add 10%. Subtract your age in dollars from the total. If the cents column is an even number add the day of the month to the total in dollars. If it’s an even number take the first 3 digits of your SSN and add that in as dollars in cents. Round the amount down to the nearest dollar. Then leave a decent tip based on the pre-discount price.
What he said. That’s total bullshit.
+1.
I hope the “pre- or post-tax” post was a joke, but if not - sales tax around here varies by county, but averages about 7%. A 20% tip on that extra amount equates to 1.4% more total tip than tipping on the pre-tax amount, or 14 cents per $10. The bill would have to total $71 before the “extra” tip amounted to $1. Inconsequential.
In this case, the alcohol is explicitly excluded from the discount. Oregon law requires that, and since this place has a fancy wine list, I’d expect them to do so even if it was legal to offer such a discount.
Nope, not a joke. I found out when someone was explaining to me how to figure the tip by taking the sales tax (which was around 7.5% here) and doubling it to get 15%.
Yes, between the reduced percentage and excluding sales tax, they probably saved a whopping buck and a half.
OTOH, I don’t think they intended to be cheap, that’s just how they’d been taught to do it.
But I have actually seen people online argue that you shouldn’t have to tip on the sales tax.
You don’t have to tip on the sales tax. You don’t have to tip at all. You can be a cheap ass bastard if you like.
I will note that I’ve seen some restaurants recently give “suggested tip” values on the credit card voucher. IIRC, they listed 15%, 20%, and 25% of the pre-tax value.
I wonder which number they use on those “minimum tip for group” deals?
Pre-discount amount. Crazy, I know.
I’m not sure if anyone on here does this, but if you do, stop. When I waited tables, I ran into this from time to time, and it sucked every time. Most places will require servers to tip out the bartenders/sommeliers based on their alcohol sales. So if you don’t tip on the alcohol, you’re just reducing their tip even further.
One of the funniest replies I’ve ever read. Thank you for making me laugh so much.
I know this is off-topic, but why were you concerned about “openly admitting this on the internet, where everyone can read it”???
It’s just tipping and I think you advised the common viewpoint. You didn’t come out as a racist or some quirky view.
!!! I am almost aghast to find someone else here that agrees with me! Well I’m really glad I spoke up, then, or the poor OP may have never known that some people believe tipping on the pre-discount price no matter how crazy it may seem. 
(Hint: I was just playing along with the joke in the thread that was already ongoing)
Always wondered just how that “tipping” ap on my phone works. Now I know why it asks so many questions.
However strange it may seem, I do start with the pre-discount price, unless the coupon says “no tipping allowed”.
Dine and dash.
100% cheaper than 50% off.
18%, same as in town.
How about a “half price” night? Same thing? We went out for sushi and the rolls were 1/2 the normal price. No coupon or anything, just half price. I said that we should have tipped on the normal price. She said on the amount on the bill, agreeing that if we had a coupon full price tip was appropriate. I didn’t see the difference.
Why would you? You still got the same service level?
Who would have thought so many years ago that some day tipping a waitress would be so complicated?