Guide:Moon Lord strategies

The Moon Lord is the final boss in Terraria. Because of its high health and its numerous, highly damaging attacks, it is generally considered the hardest boss in the game.

The following strategies will give players an easier time defeating this behemoth.

The Fight
The Moon Lord's main attacks come from the Eyes on its hands and forehead, which are also the only parts that can be damaged.

When the eyes on the hands are exposed, they will alternate between spawning Phantasmal Eyes and shooting Phantasmal Spheres. The eye on its forehead will instead charge up the Phantasmal Deathray, and then fire it based on the player's position.

The eyes can only be damaged on their "active" state and they will always shoot 2 Phantasmal Bolts before closing.

When an eye is defeated, it will detach from the main body and spawn a True Eye of Cthulhu, an unkillable enemy that uses weaker versions of the Moon Lord's attacks. The empty eye sockets will also reveal fangs which do contact damage if touched, but the Moon Lord won't directly attack with them.

Occasionally, a tongue will spawn from its mouth and chase the player. If it connects, it will inflict the Moon Bite debuff, which prevents healing from the Vampire Knives and the Spectre Hood. The Moon Leech Clots spawned from the tongue will heal one of the Moon Lord's unkilled parts for 1000 HP if they reach its mouth. It will not heal or replace any eyes in its hands or forehead if these have already been defeated.

The Phantasmal Sphere is the boss’s second strongest attack. It is difficult to escape its range, so the directional dodge provided by the Master Ninja Gear is very important.

The Phantasmal Deathray is one of the strongest attacks in the game, and the player must always watch out for it, especially on Expert mode. It can very easily finish off a player at around half health, so it must be dodged at all costs. It is only fired by the eye on its forehead, so you must be prepared for it when it opens. The safest way to dodge it is by flying over him with Wings, preferably Fishron's. It can also be dodged with a Rod of Discord by teleporting out of its path. Because of this attack it is a bad idea to keep the Moon Lord offscreen, as the player won't be able to see it coming.

The Phantasmal Bolts don't do a lot of damage, but they are hard to dodge as the Moon Lord doesn't shoot directly at the player; it instead tries to predict their position, and does so very accurately. The eyes will look at the player when preparing the attack, so you can predict it as well.

After all 3 eyes are defeated, the Moon Lord's core will be revealed, and what is arguably the hardest part of the fight will begin. The True Eyes of Cthulhu attack very frequently, quickly overwhelming even skilled players. Running away in this case is better, as the True Eyes' Deathrays have much shorter reach compared to the Moon Lord's.

Terrain preparation
If one is having problems fighting the Moon Lord, a skybridge can be built to make the fight significantly easier. Ideally, it should extend quite far from either side of your spawn point (700-1000 platform blocks should suffice). The Moon Lord will not despawn unless all players are dead, meaning you can outrun him and heal for a while if need be. However, straying too far will cause the Moon Lord to teleport on top of you, so careful spacing is required. This is of less concern in multiplayer, as the Moon Lord will only chase one player at a time, giving the others time to retreat and heal up if necessary. A long straight Minecart Track paired with the Mechanical Minecart will help you avoid most of his attacks. Make sure to hammer the ends for bumpers or make a loop to return to the straight track.

A simple roof made of solid blocks is useful for blocking the Phantasmal Deathray. Thickening the roof will also mitigate the explosions of the Phantasmal Eyes. You can open up holes in the roof to shoot through when the Deathray isn't active, or you can leave the roof without any holes and damage the Moon Lord exclusively with weapons that can phase through walls.

Asphalt can still be used to dodge the tongue if you value the ability to use Vampire Knives. When the Moon Lord teleports with his tongue already chasing you, the tip of the tongue will not teleport with him. This allows you to completely outrun the tongue, avoiding Moon Bite and allowing Vampire Knives/Spectre armor to work normally.

Terrain prep can be skipped by using a UFO Mount, although it is still wise to build some cover for the Phantasmal Rays and a 's house

Armor

 * For melee users, a regenerative set consisting of the, , and is the best available, outclassing even Solar Flare armor both offensively and defensively.
 * While the provides weaker defense and melee bonuses than the Chlorophyte Mask, it gives a significant increase to minion damage and sentry capacity. However, sentries are heavily limited by their stationary nature, making the Shinobi Infiltrator's Helmet an inferior choice unless fighting within a small arena (generally not recommended).
 * is a more accessible choice. The is the only choice you should consider if using Beetle armor, as the Beetle Scale Mail set is outclassed offensively by the combination of the Chlorophyte Mask, Monk's Shirt, and Valhalla Knight's Greaves/Squire's Greaves. The Beetle Shell will allow you to tank a few hits more comfortably, even as a non-melee user. However, it loses effectiveness against repeated barrages, so consider it only if you are prepared to spend extra effort on dodging attacks.
 * For ranged users, the strongest set consists of with the  substituted into the leg slot. Even with no investment in minion damage, the Treads' +2 bonus to minion capacity will provide a much larger total DPS increase than Shroomite Leggings, as long as you are using a Xeno Staff or either of the Stardust summoning staves. The difference is especially noticeable when using a Stardust Dragon.
 * The chest piece can be swapped with the if more survivability is needed.
 * If you are unwilling to use a hybrid summoner set, offer a slightly higher critical strike bonus than Shroomite Leggings, at the cost of 3 defense and 7% movement speed. The full Shroomite set also works, but it will be nearly impossible to safely activate its set bonus.
 * For magic users, the strongest armor is a hybrid set consisting of, , and.
 * can be substituted into the above setup for more survivability but less damage. This combination is still offensively superior to Spectre armor.
 * is another viable option, though it brings nothing to the table defensively. Its set bonus provides roughly the same DPS increase as one UFO minion. The is almost completely invalidated by the Moon Bite debuff.
 * A summoner should equip full Spooky armor and summon as many minions as possible before swapping to the Forbidden Treads and Valhalla Knight's Breastplate, in that order. This grants maximum survivability while retaining decent minion damage/capacity bonuses.
 * Those who wish to maximize minion damage while still wearing the Valhalla Knight's Breastplate should summon as many minions as possible while wearing the, , and for maximum damage bonuses, then swap to the  to summon one more minion, and finally summon two more minions while wearing the full Spooky armor set before re-equipping the  and Valhalla Knight's Breastplate, in that order. The end result is the same as above with a few stronger minions, but it is more labor-intensive and requires an extra 150 Defender Medals.
 * Those who cannot clear the Old One's Army should summon as many minions as possible while wearing, and then equip to summon one more. Be warned that this loadout is extremely frail.

Weapons
Every class will benefit the most from the weapons made with Celestial Fragments, with some exceptions.

For Melee users:
 * is the strongest melee weapon available, dealing massive piercing damage to all parts even from beneath a ceiling you might have set up to block the Phantasmal Deathray.
 * and sacrifice power for longer range. The Influx Waver also destroys Moon Leech Clots with its sword hitbox.
 * is the best melee weapon that does not deal piercing damage, so it will not interfere with the Stardust Dragon. Other melee weapons should be used with Stardust Cells.

For Ranged users:
 * is the strongest gun available. provide the highest DPS, while  are more useful for the second phase, in which you are practically forced to retreat. They also allow you to focus more on dodging the attacks, as they home in on targets.
 * with provides the highest DPS of any primary weapon, but the low velocity of Holy Arrows will hurt your accuracy unless using a Magic Quiver. If not using a Magic Quiver,  or  should be used for their high velocity, making them easier to aim.

For Magic users:
 * deals decent DPS and is accurate, but its mana cost is difficult to sustain.
 * and have higher DPS than the Nebula Blaze and lower mana cost, but lack its homing effect.
 * deals extremely high DPS if you can manipulate the Moon Lord into staying in roughly the same position. It also doesn't need to be aimed. However, it interferes with the Stardust Dragon.
 * has a fast, mana efficient projectile which can hit all 3 parts with the same shot. However, its single-target DPS is low, and it also interferes with the Stardust Dragon.
 * inflicts a potent defense-lowering debuff that the Moon Lord is not immune to.

For Summoners:
 * is best summoning weapon available, followed closely by the . Stardust Cells are preferred if your primary weapon deals piercing damage; otherwise, the Dragon's damage output is superior.
 * also works in a pinch, and its high attack speed synergizes with Betsy's Wrath if you're using it.
 * is the best sentry available for use with the Shinobi Infiltrator's Helmet, but it only works if you remain in one area. It is unlikely to contribute significantly to your DPS, but there is no drawback for using it.

Accessories
Due to the high base damage of the Moon Lord's attacks, the defense stat itself is relatively useless. The most important attributes to consider are damage/critical bonuses, mobility, regeneration, and percentage-based damage reduction. Every accessory should have the Lucky or Menacing Modifier. For hybrid summoner builds, Menacing is preferred.
 * and or  are essential for mobility. A  or any balloon accessory makes wings ascend significantly faster, which helps a lot when dodging projectiles or racing against the Phantasmal Deathray.
 * can be used as a replacement for the above, trading agility for an extra accessory slot. If more agility is preferred, a can be used to return to the ground quickly and reset your flight time, and also serves as a makeshift downward dodge.
 * Damage-increasing accessories are very important, the best of which are the, , , and . The latter two also provide bonuses to health regeneration.
 * and other knockback-preventing accessories are not recommended for this fight. These accessories are useful for tanking rapid and weak attacks at close range, which is exactly the opposite of what you'll encounter when fighting the Moon Lord.
 * The effects of the are only applied the instant a Healing Potion is drunk, so it can be kept in a vanity slot until the player needs to heal, and swapped back into the vanity slot afterwards. Be sure to use Super Healing Potions, which are absolutely worth the Celestial Fragments required to craft them, and you shouldn't need more than four.
 * and can aid with tanking the near-unavoidable damage that the Moon Lord deals in its second phase.

Potions

 * ,, , and to a lesser extent, will greatly increase survivability.
 * Any food item that provides the buff will work.
 * is absolutely mandatory for mages.
 * will increase mobility.
 * ,, and will improve DPS.
 * ,, and or  will further improve damage output for magic, ranged, and melee users respectively.
 * While not technically potions, the, , and give useful temporary buffs that can provide an additional edge.

Miscellaneous
 * As mentioned above, the is another way to avoid the Phantasmal Deathray. There is no need to worry about Chaos State, as the Moon Lord uses the attack on a timed interval, allowing for the teleport debuff to wear off.

Synchronised release
For those who want to fight the Moon Lord conventionally, it is highly recommended to synchronize the release of the True Eyes of Cthulhu. To do this, the health of the Moon Lord's head and hands must be brought to zero at a very precise moment in the True Eye of Cthulhu's attack pattern. Prepare by bringing all three of the Moon Lord's eyes to a very low amount of health, and release one. After the True Eye of Cthulhu fires a Phantasmal Deathray, another True Eye of Cthulhu must be released during the Phantasmal Sphere attack that immediately follows the Deathray. The timing is indicated by a unique noise. If done correctly, the newly released True Eyes of Cthulhu will attack in the same pattern, making them far simpler to dodge.

Duck Statues
Summoning Moon Lord then maximizing the enemy count via Duck Statues with water underneath them will prevent the True Eyes of Cthulhu from spawning when they are taken out, making the final phase far easier.

Regenerative facetank
It is possible to defeat the Moon Lord while making no attempt to dodge its attacks whatsoever. While wearing a Squire's Great Helm, Valhalla Knight's Breastplate, and Cross Necklace while fully buffed, one can heal off all the damage that the Moon Lord deals without ever being in too much danger. The leg slot can be filled with Valhalla Knight's Greaves, Forbidden Treads, or Dark Artist's Leggings to boost melee, summoning, or magic damage output, respectively. (Ranged has no good bonuses in the leg slot.) In normal mode, if you do not have access to the Old One's Army, or on, simply wearing armor pieces that provide the highest available defense will also work, as long as you are buffed with Regeneration, Lifeforce, Endurance, and Ironskin.

Simply stand in a pool of honey, grapple yourself in place, and chip away at the Moon Lord’s exposed parts. Most weapons will be far easier to aim now that the Moon Lord is no longer moving around.

Since you will be immobile for this fight, you can use accessories specialized entirely towards damage mitigation, regeneration, and damage output, with your priorities roughly in that order. It’s also not a bad idea to place a solid platform at least 7 blocks wide in the sky solely to block the Phantasmal Deathray, which will still severely dent your health bar. Doing this will make it more difficult to deal significant damage to the eye in its forehead, though weapons like the Stardust Dragon Staff, Solar Eruption, Nebula Arcanum, and Blizzard Staff will still work. Keep in mind that given the damage boosts that the Moon Lord has in Expert Mode, this is not a suitable strategy for this difficulty level.

Minecart and Teleporters
For this strategy, a very long railway with bumper ends should be made in a straight line. Make sure to build a ceiling above to block Moon Lord's Deathray.

A Minecart's speed makes it very easy to avoid the Phantasmal Spheres and Bolts, and as mentioned previously, the Deathray will be blocked by the Ceiling. When you reach the end of the track, the Bumper end will quickly change your direction while also keeping your momentum. A Teleporter wired from the beginning to end can also serve the same purpose if triggered with a Pressure Plate Track.

Shelter strategy
This strategy is based on exploiting the fact that a lot of Moon Lord's attacks can't go through walls.

A half screen-width wide, 6-12 tiles high shelter must be built. Make sure to add Heart Statues, Heart Lanterns and Honey for better regeneration. A weapon with the ability to attack through blocks such as the Solar Eruption must be used to attack him.

While inside the Shelter, only the Phantasmal Spheres will be able to hit the player, making for a very easy fight.


 * A smaller shelter is acceptable. Simply build a small 2-story house mid-air with honey on the top floor (and other items mentioned above except for heart statues), and move the nurse downstairs. When you are damaged below 200 health, simply pay the nurse for more health.


 * The top-tier armor sets sold by the Tavernkeep can make this strategy especially viable, as they allow the placement of powerful sentries outside of the 'box' and also boost the damage of the Stardust Dragon Staff. With accessories that increase minions and minion damage, they can finish off the Moon Lord in a couple of minutes or less. When using this strategy, it's important to include a row of platforms below the shelter to place sentries once the heart is visible.

Cute Fishron
This strategy utilizes the Shrimpy Truffle mount from Expert Duke Fishron. A large water arena (at least 100x20) large enough when riding Cute Fishron will greatly increase mobility, as well as saving accessory slots that would have been used for mobility. Pumps can be used to speed up the construction of the arena.

With Cute Fishron's speed, you can outrun the Leech, circle around the Deathray and dodge the Phantasmal Spheres quite easily, while also getting a small damage increase.

The Hoik Method
This is the easiest, but longest way of fighting/farming the Moon Lord. It doesn't require much in the means of equipment, other than what you would probably have already at this point in the game. It will require patience as the battle will be lengthy, but this is a sure-fire way of winning that only requires clicking the mouse to use.

A full write and example can be found here.