In Teenage Mutant Ninja Turtles Ninja Pizza Party, each player has their own stack of pizza slice cards. Each round, customers equal to one less than the number of players (except in two-player) are randomly chosen and the players all go through their stack of pizza slices one at a time, either adding the slice to their pizza or discarding it. Once they run out of cards in their stack, they take the discard pile from the player to their right to use as their new stack of slices. When a player completes their pizza of six slices, they claim the customer of their choice. This continues until all of the customers have been claimed. Points are awarded based on how many slices each player's pizza has that match the customer's favorite topping.

When building a pizza, the players must match at least one topping on the slice next to the spot where the new slice is going to go. For the sixth (and last) slice, the slice being added needs to match a topping on each of the pieces next to the open slot. Each slice of pizza has two toppings, except for special "kitchen sink" slices, that have all of the available toppings. These special slices are limited to one per pizza. If a player's pizza is completed but does not follow the rules, the player that did not claim a customer can score points for that other player's customer, using their incomplete pizza, provided said pizza DOES follow the placement rules.