Codes can only be used once, and offers can only be redeemed once per account. For multiple players using the same computer, additional offer codes can be generated by opening an incognito window and loading the offer link. You'll need to open a separate incognito tab for each code you need to generate. Individual codes remain valid for a year or more after they are generated, while offer links expire quickly (a link will be available for a minimum of 24 hours); if you are unable to access your game you can write down the offer code and redeem it at a later date.
To redeem a King's Gift code:
- Open the Shop in your game
- Click on the Offer Code button and enter your code
While rewards are now given out using the King's Gifts system, they could previously be obtained using platform-specific links: