Codes were often randomly generated alphanumeric strings of 30 characters, but now they are words or phrases with no spaces which can reward players with Currency, Resource Energy or Card Packs when redeemed. They are usually given out on the Idle Online Universe Facebook Page and in #announcements in the Idle Online Universe Discord server. Wood and Stone currencies were replaced with NRG shortly after the 3rd Q & A with Ray was released on January 11 2018.
A code can only be claimed in limited quantities, the number of which is sometimes announced when the code is handed out. Usually, the codes will expire after 1 week. Most codes will award a random resource, which scales with the player's level. Specific Bonuses and Event codes will usually give the same reward for all players.
Fun fact: The chance of getting an Inferno Card Pack from a code is 1/5000.
How to redeem a code
To redeem a code, a player needs to open the Social drop-down menu or press the key 'O', and choose Codes. A pop-up window will appear where the player can input or copy-paste the code.
To find codes, click Codes? In the pop-up window, and it will direct you to the Idle Online Universe Facebook Page. They can also be found in the #announcements channel of the IOURPG Discord server or on the Kongregate code forum thread.
Extra spaces are automatically trimmed as of 0.51 Zeta.
Note codes are case sensitive so be careful.