This form of copy-protection was included in early floppy disk releases of the game. It is a cardboard wheel, named "Dial-a-Pirate", was provided, and the player had to match the pirate shown on-screen with that of the wheel. Instrunctions from game manual:
Once you've started a program. a screen will appear displaying pirate's face (actually a combination of two faces). You will be prompted to enter a date that was significant in the pirate's life at a given geographical location. Use your Dial-A-Pirate wheel to match up the top and bottom halves of the pirate face you see on the screen. Then, locate the window on the wheel that matches the geographical location mentiones on the screen. Using the keyboard, type the date you see in the window.
Don't lose your Dial-A-Pirate wheel! Without it, you won't be able to play the game. If you lose the Wheel, you may purchase another from Lucasfilm Games.
The Secret of Monkey Island is the adventure game with point-and-click interface, memorable for its witty humor, primarily designed by Ron Gilbert, with Tim Schafer and Dave Grossman for LucasFilm Games company in 1990 for Amiga/Atari ST/IBM PC. The game introduces Guybrush Threepwood, a youth who desires to become a pirate. At the beginning of the game, he washes up on the Caribbean island of Mêlée. The atmosphere was based on that of the Pirates of the Caribbean theme park ride. The Secret of Monkey Island was the fifth game built with the SCUMM engine, which was heavily modified to include a more user-friendly interface.