Gameplay wise, the Chalice Dungeons open up an entirely new way to experience Bloodborne. Whereas the Core Game is Campaign-based, the Chalice Dungeon game mode is completely based around a single game.
When diving into a Chalice Dungeon, Hunters will be faced with random enemies as they explore the catacombs and rooms; all enemies from the Core Box, as well as enemies unlocked via Stretch Goals, can appear here, with devastating new versions to represent them in the crypts.
The goal of each game in the Chalice Dungeon is simple: find the Boss Room, find a way to unlock said Boss Room, and then venture inside for a final confrontation with an unknown horror.
—description from the publisher