Slime Rain

"Slime is falling from the sky!" Slime Rain is a minor event that consists of frequent spawns of Green, Blue and Purple Slime and rarely Pinky. It occurs randomly, signaling its beginning with the message "Slime is falling from the sky!". Slime Rain continues until 150 Slimes have been defeated, at which point King Slime will spawn. If King Slime has previously been defeated, he will spawn after only 75 Slimes have been defeated. The event ends shortly after he is defeated or despawns.

A Slime Rain can only occur if at least one player in the world has over 140 maximum health and 8 defense (except in Expert mode, where it can occur before meeting the criteria – with a significantly decreased chance). Given those criteria, a Slime Rain has an approximate 4.9% of chance of occuring in a pre-Hardmode world per day (approx. 3.3% in Hardmode). If King Slime has not been killed yet, the probability for a Slime Rain to occur is doubled.

While a Slime Rain is active, Green, Blue, and Purple Slimes will appear to fall in the background. It can last anywhere from 9 to 15 in-game hours. If the player fails to defeat 150 (or 75) by the end of the Slime Rain, the message "Slime has stopped falling from the sky." will appear and the Slime Rain will end naturally without King Slime spawning. Slime Rain does not end if you leave the world.

Tips

 * The event can be avoided entirely by staying indoors or underground, as it can end without any player interaction after a certain amount of time has passed.
 * The high spawn rate of Slimes during a Slime Rain, including Pinky, greatly facilitates farming for Gel, Pink Gel, Slime Staff, and the Slimes' Banners. King Slime will also offer loot that is useful at the beginning of the game.
 * An enclosed shelter with a 1×1 hole in the wall will allow you to fire arrows and use Yoyos from relative safety. However, once King Slime spawns, it is advised to leave, as he can teleport into the shelter and trap the player.
 * Spawn rate can be increased with a Water Candle.

Trivia

 * The Slime Rain effect in the background can be seen before the event is announced if the player goes up high enough.
 * Some Slimes appear to spawn in the air above the player which results in them falling from the sky, giving the term "rain" a literal meaning.
 * This is the only combat event that does not cause a change in music, as the only theme that plays is the Boss 1 theme when King Slime spawns.

History
Schleimregen 史莱姆雨