Guide:King Slime strategies

"The lord of all things slimy."

King Slime is an optional Pre-Hardmode boss. Due to its low stats and predictable attacks, it is considered the easiest boss in the game by most players.

Spawn Condition
King Slime can be spawned by fulfilling any of these conditions: It must then be defeated before all the involved players die.
 * Naturally on Grass beyond the Dungeon and Jungle (this is approximate: it might be farther or nearer depending on world size);
 * Naturally by Natural-occurring Slime Rain;
 * Using.

Battle
King Slime is no different than a normal Slime: it moves by hopping to the player. Unlike other Slimes, however, it has a large pool of health due to its Boss status, and it's huge. This makes King Slime an easy target, but he jumps far and unpredictably; the height varies depending on the distance between him and the player. Failing to predict its jump destination can result in the player getting damaged.

Getting too far away from King Slime will make it teleport to you, meaning that you cannot escape by simply running off the screen. However, this can be taken advantage of, as it can get stuck in enclosed spaces.

As King Slime gets damaged, it gets smaller. This makes it more mobile and harder to hit, having less issues to escape small enclosures (should it fail, however, it might teleport instead), and it spawns lesser to harass you. These can make you waste ammo on them instead of the King Slime, so the use of piercing weapons or ammo is important.

The main difference between these versions with is that it does not teleport; it can be eternally stuck in small to medium-sized enclosures if it spawns there, but is mostly the same.

Expert mode
There are not many changes about the King Slime itself besides its higher Damage and Health. However, when damaged it will spawn in addition to regular Blue Slimes. Those can throw volleys of spikes at a short distance, so having a weapon which can pierce multiple targets and attack from a range will be necessary to avoid being bombarded to death.

Terrain Preparation
 King Slime is one of the few bosses in the game that lack the ability to go through blocks. This can be exploited in multiple ways:
 * On, climbing on a 35 blocks above the ground allows you to attack him at range safely without him teleporting onto you. Add extra rope to give yourself a margin of error, or to retreat and heal if need be. Using this method makes potions, higher damaging weapons, armor, and movement accessories optional, as the player will not need to dodge attacks or mitigate damage. In , this exploit used to work, but after 1.4, this exploit was patched by having King Slime teleport to the player or jumping very high.
 * Make one or two platforms above the ground; King Slime will eventually teleport to ground level and you can easily hit him from the platforms.
 * A flat area with small room below it with Platforms as roof for the player. King Slime can't enter small rooms and thus cannot reach the players in it.

It is no longer possible to exploit the King Slime's large size in versions, as he can teleport to unreachable areas.

It is also good to place and, as they increase the player's health regeneration. A and a  can also help increase mana regeneration and movement speed respectively.

Armor
Armor is not very important in this fight. However, it is recommended to have at least, as it is easy to obtain and provides a decent amount of defense. More armor is always better. However, in Expert or Master Mode, better armor is recommended due to King Slime's buffed HP and attack power.

Weapons
Most weapons can be used to fight this boss without difficulties. Piercing weapons may be preferred, to hit both the Blue Slimes and the King Slime himself.


 * As a Melee character, Swords are a bad idea due to the amount of Slimes the King will spawn, but the, , (or  on Console and Mobile editions of the game, as the Terragrim hasn't been added)or  should definitely be used if obtained.
 * An or  are great at attacking him from a distance.
 * The is also helpful. If the player is willing to adventure into the Underground Jungle, the  is a great choice.
 * Ranged users should bring a or
 * or are the preferred ammo type, due to the high single target damage of the former and the piercing effect of the latter.
 * Magic users should bring at least or staff.  or  are the best available.
 * Summoners should bring either a or a, and  if affordable.
 * If the player has only acquired the, one may use it.
 * Throwing users should bring a bunch of or .  can deal a lot of damage, although they may damage the player if used recklessly.
 * If has been defeated,  should be crafted, as they are very powerful throwing weapons.

Accessories
Like weapons, most accessories can help:
 * ,, , or a  can assist with avoiding damage or running away in bad situations. These should be combined with Rocket Boots at the Tinkerer's Workshop if the Goblin Tinkerer has been rescued.
 * The is also a very good accessory since its ability to hover can make the King Slime unable to reach you.
 * On the, King Slime will teleport to the player without regarding the player's location.
 * ,, , , or (if you have defeated the Goblin Army) can also help with any vertical movements. If one has a , they should combine it with a bottle accessory, making it even better.
 * A can be useful to increase rate of regeneration while avoiding being damaged by King Slime, and a  can help to refill Mana faster.

Potions

 * can help by reducing the damage received.
 * help recovering life lost.
 * Any food that grants the, or any other high up buffs from food.
 * to better evade the teleports and run under the jumps if needed.

No teleports Strategy

 * Build a one-block thick wall 18-20 blocks high;
 * Create a walkway between 35-50 blocks long with platforms for maneuverability;
 * Make sure a is nearby.
 * Use any long-range weapons (Yo-yos, Bows, Gem Staves or Throwing weapons).

Rope Strategy
Doesn't work on. An easy way to defeat King Slime is to do this:

Make a flat ground (about 30 blocks area)


 * Make a rope around 30 blocks high from the ground
 * Use any weapon that has range (Bows, Staffs, Shurikens, Grenades, etc.)
 * Climb up to the rope, and shoot King Slime. He will be unable to attack you.

This way, you are practically invincible from him, as he cannot jump to you, and there is no surface for him to teleport on. Be careful if doing this strategy during Slime Rain, since a slime can fall from the sky and knock you off the rope.

Lava pit Strategy
Because the King Slime can be harmed by Lava, a good strategy is to use a to make a long strip of land with a small amount of lava (shallow enough so items don't burn) and then make some widely placed platforms. You can jump, use rocket boots, or use a grappling hook to move between platforms. Just be careful to not jump in the lava if you don't plan to use. This strategy works with his teleports, and the minions will all die from falling in the lava. You don't have to focus on fighting, because the lava will dish out major damage. You can also skip the platforms, and use a Obsidian Skin Potion, and just evade by running under the slime, or using to fly over.

Minecart Strategy
Another strategy is to make something that could help you later, a long Minecart rail path. If you build it just high enough, he will not be able to teleport or jump on you. His attacks rely on you being on the ground. To the AI, it seems that you are on the ground, so he just sits under you and occasionally jumps, making him an easy target.

Death Box Strategy
Upon the player's death, the King Slime will attempt to travel off-screen in order to despawn. However, the King Slime cannot travel through solid blocks, so he can easily be trapped in a small area until death.


 * A solid box must be constructed. The box should be large enough to hold the King Slime, yet not so large that he can still wander off-screen.
 * A bed should be placed within the box. In order to make the bed usable, it may be easiest to build a small cubicle within the box to hold the bed.

Before the King Slime spawns, the player should be inside the box with his spawn set on the bed. Once the King Slime awakens, he will teleport within the box to attack the player. The player should deal any damage he can to the King Slime at this time. The King Slime should inevitably kill the player and attempt to hop off screen. However, he will find himself trapped in the box and will not be able to leave. The player will respawn at the bed and is free to deal any additional damage to the King Slime before his next death. Repeat this process until the King Slime is defeated.

Weapons and traps that can deal damage to the King Slime during a player's death will greatly speed up the battle, such as the, s or a thin layer of lava.

Since this strategy revolves around the player's death, hardcore players should avoid implementing this strategy.

In 1.4 this method is no longer viable, as the King Slime simply withers away upon your death.