Message Bottles (known as Note in a Bottle in Animal Crossing: Wild World) are items that occasionally wash up on the beach. They are glass bottles which contain a letter and may sometimes contain a present. They were originally introduced in Animal Crossing: Wild World, and have since appeared in Animal Crossing: City Folk and in Animal Crossing: New Horizons.
In Wild World and City Folk
Notes in Bottles can only be found in Animal Crossing: Wild World, but can be obtained in Animal Crossing: City Folk if a player moves from their Wild World town and had one in their catalog. They will all say something different. The player can also buy bottles in Tom Nook's store for 200 Bells each and, unlike most items, the store will have unlimited stock. If the player writes something inside a bottle and releases it and a friend has done the same, when the two connect through Contact Mode/Tag Mode, they will each find their friend's Note-in-a-bottle washed up on their beach. They can be saved in the Town Hall like letters. Presents can also be sent along with the notes, but it is unknown if they reach the other end. The player may also find various random notes in a bottle on the beach with a random message enclosed.
Mail differs depending on whether it is from a real person or Nintendo, as a note from a real player will always start with "Dear Some Stranger," unlike a Nintendo note-in-a-bottle.
In New Horizons
In New Horizons, the Message Bottles now contain a note from a random villager along with a DIY recipe relating to that villager's personality. During special events such as Bunny Day, themed message bottles may be found on the beach. Similarly, they contain a themed note and DIY recipe.
In Gekijōban Doubutsu no Mori
Throughout 🎬 Gekijōban Doubutsu no Mori, Ai finds several notes in bottles on the beach that tell her to plant cedar trees for the Winter Festival and are implied to be sent from an alien. It is later revealed that Gulliver sent the messages to impress the residents of Animal Village while he masquerades as an alien.
A player finding a Note in a Bottle in Wild World.
A randomly-generated Note in a Bottle message in Wild World
Five notes in bottles in the observatory in Gekijōban Doubutsu no Mori
A Message Bottle found on the beach in New Horizons
A Bunny Day-themed message in New Horizons