An emulator is a demo of a source game. They are unlocked by playing all of the normal story levels that originated from that game.
- LEGO Star Wars: The Video Game
- LEGO Star Wars II: The Original Trilogy
- LEGO Star Wars: The Complete Saga
- LEGO Indiana Jones: The Original Adventures
- LEGO Batman: The Videogame
- LEGO Indiana Jones 2: The Adventure Continues
- LEGO Harry Potter: Years 1-4
- LEGO Star Wars III: The Clone Wars
- LEGO Pirates of the Caribbean: The Video Game
- LEGO Harry Potter: Years 5-7
- LEGO Batman 2: DC Super Heroes
- LEGO The Lord of the Rings
- LEGO City Undercover (Wii U exclusive)
- LEGO Marvel Super Heroes
- The LEGO Movie Videogame
- LEGO The Hobbit
- LEGO Batman 3: Beyond Gotham
The goal of the emulator is to get 100% in that emulator. Once the player gets a 100%, they get a Gold Brick for LEGO All-Stars. While whatever they do in the emulator wouldn't affect the All-Stars game percentage, the gold brick certainly will.
The game gets one save file per emulator. LEGO All-Stars: The Compilation Crossover has two packages for system memory: One for the three save files and the other for the emulators. When the player boots up the game for the first time, the game checks the console memory. If no emulator data is found but save files are present for the past games, the game will ask if the player would copy the save data into the emulator data. The copied data will give the player a boost in progress in the emulator and can give the player an instant Gold Brick for unlocking an already complete emulator.
The emulators undoes all the changes of LEGO All-Stars and reverts the games back to their original state. Even the graphics are downgraded to the best of that game. However, the emulator could still have a few changes such as adding "Central" to the pause menu. The emulator is the only way to get to Dexter's Diner. The GamePad can also be used for games that predate the Wii U. There is also a way to bring characters from other games into the emulator with the Bring Anyone in Emulators Red Brick from the main game's Research and Development level. However, foreign characters especially Superman in LEGO Star Wars can get seriously nerfed, and while the grid is the same in the main game with the extra on, the computer won't choose outsiders in Free Play.