The Copper Key was the first of the three keys needed in the quest to find Halliday's Hidden Egg. It was first mentioned in Anorak’s Invitation. It is inscribed with the following clue to discover the First Gate:
What you seek lies hidden in the trash on the deepest level of Daggorath.
This clue is on the Key.
The Copper Key is located on the planet Ludus, within the Tomb of Horrors; to earn the key, the character must defeat Acererak the Demi-Lich in two out of three games of the arcade game, Joust, which Wade practiced with Aech