Carnival World Buffet is about par for course on a low-end casino buffet, but very large and with lots of food, and insanely overpriced. Wait in line for an exceptionally slow and poorly designed kiosk to charge you $20 per person for a buffet, plus tip. The kiosk prompts you for 15 or 20% tip, which is more than what you traditionally pay at a self-service buffet, and there is no option to tip a more conventional 10%.\n\nFor your $25 total, you can browse stations ranging from mediocre pizza to burgers to Chinese food. Some of the items are good, particularly the burgers, but for the most part, everything here is only a step or two above fast food, if that. The Mexican food, for example, had quesadillas that I think had American cheese in them with guacamole that consisted almost entirely of sour cream. And breakfast food, curiously, is dispersed across the buffet: waffles might be with the burgers, but eggs are probably next to the Chinese food.\n\nYou might be wondering why I checked in twice here. Did I mention you're a captive audience at the Rio? It's off-strip, so unless you want to take a cab somewhere, you're hosed. And I was with a group.\n\nThe bottom line is, you're paying $25 for $4 worth of crappy food with an outrageous gratuity for someone who only brings you silverware and a soft drink (alcohol is at a station only).