Yes, on the dining plan, the tip is included BUT on the buffets, if we were taken care of fairly promptly with drinks, clearing plates, friendliness, we'd still leave a nice tip OOP. It's nice to show a small amt. of appreciation. BUT there were also a place or two on our last trip where we'd wait a good while for drinks(or re-fills) and/or the waitstaff may have been not friendly and we didn't leave anything but what they got in the dining plan.