Lexi, 95% of the time the service charge is actually the gratuity.

I always scour the room service menu and if I can't specifically find the word "gratuity", then I generally ask while I'm placing the order as I feel cheap asking the server. Edited: but if i don't get an answer over the phone then i will ask the person delivering the meal

If it's been included, I'll often add an extra dollar or two anyway. And if it hasn't, then I'll tip 15-20%