An Easter egg in a game is a hidden message, joke, reference, or feature deliberately placed by its creators for players to discover. It has no required role in completing the game and rewards curiosity alone.
The practice is commonly credited to Warren Robinett and Adventure for the Atari 2600, released in 1980. Atari did not credit its programmers, so Robinett hid a room displaying the text Created by Warren Robinett, reachable only by carrying a single pixel object, the Gray Dot, to a specific wall. When the secret spread, Atari kept it and described such hidden messages as Easter eggs for players to hunt, which gave the practice its name.
Modern Easter eggs range wider than a signature. Developers hide portraits, developer rooms, parody items, nods to earlier games, and elaborate secret levels that can take communities years to find and document. Some are found by exploring past visible boundaries, others by entering unlikely input sequences or reading a game files, and a few remain rumoured long after release.
Easter eggs persist because they cost little and signal a human hand. A player who finds one feels the game was made by people with a sense of humour about their own work, which is exactly the credit Robinett was asking for in 1980.
In play"The painting in the hallway is an Easter egg that references the studio first game."