I've been living abroad for over half my life in a country where tipping is not the norm. At most you would round up. 19€ bill? Here's a 20, keep this change.
Going to the US soon to visit family and the whole idea of tipping makes me nervous. It seems there's a lot of discussion about getting rid of tipping, but I don't know how much has changed in this regard.
The system seems ridiculously unfair, and that extra expense in a country where everything is already so expensive really makes a difference.
So will AITA if I don't tip? Is it really my personal responsibility to make sure my server is paid enough?
If you're sitting down at a table having a meal with a waiter who is taking your order and bringing you your food then yes, 15-20% tip is strongly encouraged. If you're going into a place where you order your food at a counter and pick it up yourself to take to your table or back to your home then tipping is not necessary.
Culturally, 18% is the absolute minimum nowadays. An average tip is north of 20%.
I typically do 20% and round to the next dollar. So if the meal was $56.14, I would calculate $5.60 as approximately 10%, double it to $11.20 and then add 66 cents for a tip of $11.86 do the final total is $68.00.
The servers only enter the total line in the system, so this makes it easier for them.