World Evils

Each world receives one of two evils: Corruption or Crimson, never both. The choice is decided by the world seed and cannot be picked by the player, so a seed always produces the same evil. The first time a player opens the right chest in a Nether fortress, the evil reveals itself, and the world seeds that do not yield the Nether generate a different discovery instead.

Infection spreads slowly across the ground. Standing on infected ground long enough transforms nearly any block into the infection's version, including artificial blocks. Walking away does not pause the spread, and it keeps going while the player is looking elsewhere. A settings page lets server owners throttle the spread or switch it off entirely on weaker hardware.

Hallow appears as the opposite of both evils. Light blue grass and trees appear where the evil does not reach, water can turn completely magenta, and crystals grow in place of the infected terrain. Evil-themed gear is made only from materials found in altars and caves, and the Crimson and Corruption enemies drop it. Each evil expects a player to arrive with stronger gear than the enemies they fight in the infected areas.