Guide:Eater of Worlds strategies

"Screams echo around you..."

The Eater of Worlds (or EoW) is one of the bosses in Terraria. It is found in The Corruption. Preparation for this boss is both extremely helpful in the fight, and is relatively simple to complete. The following are some hints, tips, and strategies to help you defeat it when first encountered.

Spawn Conditions
Eater of Worlds is spawned by fulfilling one of these conditions:


 * Breaking three ;
 * Using.

You must then defeat Eater of Worlds within the Corruption: getting out of it will make it retreat and despawn.

The Fight
Eater of Worlds is a huge multi-segmented worm, and thus, its parts tend to linger for a while. You can damage those parts with penetrating weapons and ammos to deal a lot of damage. It is also very mobile if you decide to fight in Corruption chasm. Thus, it's important to reach the surface (and its arena if you made it, check below for more info).

Beware that, when a segment dies, the segments in front and behind will detach and separately attack the player.

Managing the Worms
These two worms form a new head and tail, and they will make the fight more difficult. To prevent that, you can try to prioritize the Head segment, which has the lowest defense of the segments, but it is also the most damaging one. Alternatively, you can prioritize the Tail segment, which however is the opposite (more Defense, less damaging).

Careful management of segments can reduce the number of smaller, harder to hit worms. In this case, prioritize the use of non-penetrating weapons, and hit its head and tail. If you destroy a middle segment, concentrate on the smaller worm, since the larger one can be easy to predict and dodge.

Expert Mode
Eater of Worlds can shoot, and touching the worm itself causes  debuff. And your explosives deal less damage against it, to the point to making them more expensive than its alternative throwing, equally-damaging, weapons.

Weak debuff can be annoying to deal, as you receive 3 more damage from all forms of damage.

Vile Spit can be hard to dodge if you decided to fight the worm inside the chasm, thus fight it on surface instead. However, Vile Spit's trajectory can be easily predicted: it has a fixed trajectory. You can easily dodge it if you constantly move.

Master Mode
In master mode, the Eater of Worlds will constantly emit  while above ground, as well as moving more aggressively. This makes fighting them above ground impractical without a means of dealing with the spit. As the spit is destroyed when attacked, using a weapon which constantly attacks around the player such as a mace will effectively shield them from the projectiles, although these weapons often lack the penetrative effectiveness of other options. It is theoretically possible to carve out a similar arena underground, but generally impractical.

Terrain preparation
The player must be in The Corruption to summon the Eater of Worlds; moving too far away from the biome during the battle will cause it to flee.

The Eater of Worlds is a very large Worm enemy, so dodging it may prove to be difficult. You may want to try fighting it on the surface instead of underground. If summoning this boss via breaking shadow orbs, be sure to provide yourself a quick and safe escape back to the surface where your arena will be. A room with a Bed next to your arena can let you teleport there easily, but be careful that the path from orb to arena does not go through any non-Corrupted areas (lets the boss despawn). When making your arena on the surface, you have some options:


 * In Normal mode, make it fairly tall, thin, and easily climbable with many Platforms. That way, not only you can see it coming, but this will force it to climb in a relatively straight line, leaving large portions of its body exposed, and vulnerable to piercing attacks.
 * In Expert mode, due to the frequency of the Vile Spit attack, the Eater of Worlds will become much harder to dodge. You need to make an arena to compensate for this new attack. Build a regular row of platforms (your choice of length) in the sky. After this, build a long row of blocks (at least 50 blocks long) next to it. While you fight the boss, all of the Vile Spit projectiles will be blocked by this block barrier. If you built the arena low enough, the boss will be able to travel on your defense platform-- Watch out for this, but also utilize it to attack it when it's vulnerable.
 * To not get interrupted by Soul Eaters, it's recommended to place a Soul Eater Banner to their minimize damage. You can obtain one by killing 50 Soul Eaters.
 * Whichever option you choose, make sure the arena doesn't go too high. If it goes too high and the Corruption background disappears, the Eater of Worlds will start despawning.
 * It's also recommended to build your surface arena above a valley. While it's still above the ground, the hills on either side will provide higher ground for the Eater of Worlds to get to you and make your arena less effective.

If you don't want to fight it on the surface, it's alright to fight it underground instead. If you are breaking Shadow Orbs, hollowing out an entire arena every third orb or escaping to a surface arena may not be practical; you should modify the terrain around you to have a quick path of escape to a space with good horizontal clearance and any hazardous terrain smoothed out or boarded over. Consider placing platforms periodically to provide extra maneuverability.

If you have a Pre-Hardmode Autoswing weapon such as the Falcon Blade or a Katana, you can use a Grappling Hook and hook it to the ground to be able to remain stationary. Alternatively, a Cobalt Shield or an Obsidian Shield can be used to become immune to Knockback. If you happen to have any Shadow armor, it could be useful, as it increases your melee speed. Once the Eater of Worlds has been summoned, begin swinging. As the Eater of Worlds tries to inflict damage by passing through you, the Autoswing weapon will destroy its sections fast and effectively, and the fight will be over fairly quickly. This can also be used as an effective farming technique.

Armor and Accessories
Gold armor or Platinum armor is recommended. You can get Shadow armor by killing enough segments of the boss without necessarily defeating it, or Ancient Shadow armor by farming the Eaters of Souls.

It is possible to kill the Eater of Worlds with just Iron armor or Lead armor, but the fight will be a bit more dangerous. Pumpkin armor is another viable option, rewarding slightly less defense than iron, but increasing your damage output, which can ensure the fight is completed quickly.

Rocket Boots are recommended as they can help with dodging.

Accessories with Menacing or Warding will be most efficient here, but are not required.

Weapons
For Melee users:


 * Large swords like the War Axe of the Night can deal damage evenly if swung repeatedly at the long worm's arcing body.
 * The Chain Knife is also a great weapon to kill the boss, but takes a while to kill it. If you have a Ball O' Hurt from breaking Shadow Orbs, or a different flail, you can easily swing it into the EoW and inflict massive damage to many of its segments. This method requires more defense and/or health however, and preferably a way to avoid knockback.
 * If you are lucky enough to find an Enchanted Sword Shrine and obtain an Arkhalis (or Terragrim), you may find it to be very effective against the worm.
 * As mentioned above, an Autoswing weapon such as the Falcon Blade or a Katana could be very useful. If you manage to find one with one of the speed increasing Modifiers, it may prove even more useful.

For Ranged users:


 * Guns can be very effective at killing worms.
 * The Musket does 33 damage and is easily obtained by breaking Shadow Orbs and is a great gun to get for killing the Eater of Worlds.
 * The Harpoon is a excellent choice of weapon, but it works best close to the Eater of Worlds and requires the Goblin Army to be defeated first.
 * Bows don't have as fast a rate of fire, but by farming Devourers for their teeth and upgrading to Unholy Arrows, the piercing effect makes them a great choice.
 * Jester's Arrows work just as well, if not better, and are fairly easy to get.
 * The Demon Bow is also relatively easy to get by this point and will work well, but even the Platinum Bow can be used. If a shot can be lined up, about 30 damage can be done to 10 segments, finishing the fight very quickly.
 * The Star Cannon, available after defeating the Eater of Worlds at least once and enabling meteorite strikes, makes a mockery of it- ripping through multiple segments and destroying virtually any segment in one hit.

For Magic users:


 * The Vilethorn will not deal damage as quickly as other methods, but will have a balanced damage distribution throughout the entire body. It's obtained from Shadow Orbs in the Corruption. Furthermore, this is a relatively safe weapon to use against the worm as it can be deployed in the worms path and will remain for a short time doing damage while giving you time to dodge.
 * Ruby or Diamond Staff can also pierce multiple parts and deal great damage, while using little mana.
 * Also, a Bee Gun can be very effective against the Eater of Worlds, because of its fast-rate homing bees, and can be further enhanced with the Hive Pack, for Expert players.

For Throwing users:


 * Non-explosive consumables, such as Shuriken and Throwing Knives, can be effective since they penetrate segments, meaning that they hit multiple times while allowing the player to keep a safe distance.
 * Explosive consumables, like Grenades and Beenades are very effective, killing all pieces caught in the blast. The player should be careful, however, to not get caught in the blast themselves.
 * Spiky Balls are especially useful, as they can be thrown down where the Eater of Worlds is likely to surface.
 * Molotov Cocktails are extremely effective against the Eater of Worlds, leaving behind multiple flames on the ground that do ~40 damage each and hit every segment that moves through them.

For Summoner users:


 * The is a great summoning weapon against the Eater of Worlds due to its attacks piercing the segments of the Eater of Worlds.

Potions

 * Ironskin and Regeneration Potions can really help mitigate any hits you take.
 * Hunter Potions can be very useful in spotting the Eater of Worlds as it burrows, making it easier to fight even without a raised platform.
 * A Cooked Fish or other food item will also give you a small buff to all stats.
 * The Thorns Potion will damage the Eater of Worlds every time it hurts you and is easy to craft.
 * An easy way to get out of the chasm if you wish to fight on the surface is to use a Gravitation Potion and a Lucky Horseshoe.

Farming
The EoW can be a good source of money if you sell the and  that it drops. With endgame, or even late pre-Hardmode, armor and weapons you can quickly defeat this easy-to-summon boss. Once you have recruited the Tavernkeep, his Lightning Aura sentries are deadly against the EoW, because once the head has passed a given point, all the body segments must follow. Even the Rod can kill the boss "cleanly" (from the head back) in a few passes, while the player simply evades the worm and renews or moves the sentry as needed.

Hardmode weapons that swing continuously such as the Phasesaber and Excalibur are extremely effective against the Eater of Worlds. Spears and higher tier Flails can also quickly dispose of the EoW. Simply grapple yourself to the ground (or use a Cobalt Shield) and keep attacking/keep your flail below you by holding. If you have Molten Armor, you will be able to take any damage the Eater of Worlds dishes out, as its killed segments tend to drop Hearts, which will heal you.

The Medusa Head (easily obtained with a statue farm) offers a fairly quick execution, because it hits every segment in line-of-sight. With an arena high enough for the EoW to emerge completely from the ground, plus a modest damage bonus (+15% or better), it can destroy the entire boss in three strikes. However, this is much less practical in Expert mode, due to the Vile Spit projectiles.

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