Terraria Wiki

Miss the old Hydra Skin? Try out our Hydralize gadget! Visit the preferences page while logged in and turn on the gadget.


Terraria Wiki
This is a Guide page.
This is a Guide page.
This means the page will walk you through a specific task, strategy, or enemy/boss fight.
Status: Subject to revision (This Guide does not meet certain quality standards and may be heavily outdated.)
  • Issues:
     • Most likely outdated since 1.4. Remember not to delete pre-1.4 content; use {{eicons}} and {{eversions}}!
  • Retinazer Trophy.png "This is going to be a terrible night..." Spazmatism Trophy.png

    The Twins are the Hardmode version of the Eye of Cthulhu. They are part of the trio of the mechanical bosses, alongside with The Destroyer and Skeletron Prime.

    The TwinsHardmode exclusive
    The Twins.png
    Classic mode icon.png Classic
    Expert mode icon.png Expert
    Master mode icon.png Master
    Max Life430006450082237 (total)
    KB Resist100%
    Immune toPoisonedConfused

    Spawn Condition[]

    The Twins can be spawned by fulfilling either of these conditions:

    • Smash a Demon AltarDemon / Crimson AltarCrimson Altar. They will then have a 10% chance of appearing when night falls. Note that this condition is shared with the rest of the mechanical bosses, which increases as more of the three are defeated. This method will only work if The Twins have yet to be defeated;
    • Use a Mechanical EyeMechanical Eye during Hardmode at night.

    The Twins must be killed before dawn (4:30 a.m.), otherwise they flee and despawn.

    The Fight[]

    The Twins, as the name suggests, are two separate monsters, both of which must be defeated. They have a combined health of 43,000 / 64,500, shared between them. Retinazer is distinguished by its red iris and lasers, while Spazmatism can be identified by its green iris and cursed flames projectile.

    When an Eye is reduced to 40% of their maximum health, it will transform, gaining a slight boost in offense and defense. Each Eye transforms independently once reduced to 8,000 / 12,000 HP (Retinazer) / 9,200 / 13,800 HP (Spazmatism); the other eye remains in its original form until it is reduced to the appropriate amount. When one is destroyed, the other will continue attacking in the same pattern.

    It is a good idea to focus on one eye, since the fight becomes easier if a single eye has been defeated. Additionally, the fight becomes considerably harder if both eyes are on their second form.


    In its first form, Retinazer will fire lasers at the player at a steady but somewhat slow rate. This is occasionally interrupted by charging attacks, which mirror that of its partner. Retinazer does slightly less damage than Spazmatism, but this is offset by its higher accuracy thanks to the speed of the lasers. When not charging, Retinazer will always be aligned diagonally with the player, positioned above them.

    When it changes into its second form, it will no longer engage in charge attacks. Instead, its lasers will progressively fire at a faster rate as it loses health. This is occasionally supplemented by a weaker but much more rapid laser attack that tracks extremely well. To avoid this, try to fall as fast as you can, and you can be left unscathed. With wings it is possible to "zig-zag" up and down to dodge the lasers. This is made trickier as the fight goes on, with Retinazer using quicker lasers that are much harder to dodge.


    Spazmatism, like Retinazer, alternates between firing Cursed Flames from a distance and engaging in charging attacks. The flames do more damage than the lasers, but are not as fast and thus easier to dodge. However, the Cursed Inferno debuff can be very dangerous for its high damage over time and its ability to stop health regeneration. Its charge attacks are faster and more agressive than Retinazer.

    Spazmatism's second form changes its attack pattern dramatically. Its Cursed Flame attack becomes a constant stream of flame, which will last for several seconds (and deal large amounts of damage). However, it does not chase the player as quickly as it does in its first form, making avoiding the attack somewhat easier. Once it stops spewing flame, it will charge with greatly increased speed, which also does a lot more damage. Much like Retinazer, it is a good idea to fall as fast as you can while it is charging, and you should be okay. Redirecting Spazmatism's charges is easier than it sounds; if you jump as he slows down, he will charge over you. This causes Spazmatism to charge at you from either above or below, making him easier to dodge if you just run.

    General Strategies[]

    General Tips[]

    This content is transcluded from Guide:Practical tips § Combat.

    • For nocturnal bosses, starting the battle just after the sun sets (7:30 PM) will provide the maximum amount of time to defeat the boss. In Hardmode, the Moon CharmMoon Charm and/or Moon StoneMoon Stone and their upgrades are also useful at night.
    • Boss battles can be won or lost before the battle ever starts. Choose your equipment and have it ready; find and/or make potions and placed buffs; use the highest-tier food you have available; set up an arena appropriate to the boss; learn the strategies for the boss you're facing.
    • Prepare your Boss-fighting arena with adequate lighting, CampfireCampfires and Heart LanternHeart Lanterns for health regeneration, and Star in a BottleStars in Bottles for mana regeneration if you use magic. Bast StatueBast Statues will provide a significant defensive boost. Garden GnomeGarden Gnomes and (if underground) proper torch placement will reduce damage taken and increase damage dealt due to the luck. Note Torch God's Favor helps with this. HoneyHoney pools can also be used for extra health regeneration.
    • SunflowerSunflowers provide the Happy! buff to players within a 50-tile radius, which grants a +10% movement speed bonus and 17% reduction in enemy spawn rate.
    • Always carry around a stack of the highest-tier healing potion available, as relying only on natural Health Regeneration is not a good idea. Depending on the game stage, this can include items such as Mushrooms or Honeyfins. On the Desktop version Desktop, Console version Console, Mobile version Mobile, and Nintendo Switch version Switch versions, Restoration Potions are healing potions with a shorter cooldown.
    • It is suggested to build houses for the DryadDryad and the NurseNurse NPCs in your arena. The former casts the Dryad's BlessingDryad's Blessing buff, which increases your defense and provides you with a thorns-like effect, while the latter can heal and remove debuffs instantly, at the cost of some Silver Coincoins.
    • Bosses are displayed on the Minimap: Follow the boss's icon to track it when you're struggling to find it. You can identify the boss icons by checking their respective wiki pages.
    • Once you have freed the MechanicMechanic in the Dungeon, you can use WireWire to enhance your arena with Dart TrapTraps and helpful Heart StatueHeart and Star StatueStar Statues. The former helps to damage the enemies, though be careful to set them up correctly in order not to hurt yourself during the battle. The latter will spawn heart and star pickups, respectively. Connect these devices to 3 Second Timertimers.
    • It may be useful to summon and kill the Eye of Cthulhu or King Slime before summoning any harder boss in order to spawn an extra one-use pool of Hearts. Note that this will prevent any Heart Statues from spawning new Hearts.
    • Remember to use the Sharpening StationSharpening Station, Ammo BoxAmmo Box, Crystal BallCrystal Ball, Bewitching TableBewitching Table, and Slice of CakeSlice of Cake before you go to explore or battle bosses/invasions. These will give boosts that are useful to take, with the first four being class-specific. They give SharpenedSharpened, Ammo Box (buff)Ammo Box, ClairvoyanceClairvoyance, BewitchedBewitched, and Sugar RushSugar Rush, respectively.

    Terrain preparation[]

    The Sky above the surface is highly recommended for the Twins arena, as vertical movement is required to dodge most of the attacks.

    • A very long Sky Bridge (if possible made out of Asphalt BlockAsphalt or Frozen Slime BlockFrozen Slime Blocks) is optimal. Continuously running with Spectre BootsSpectre / Lightning BootsLightning / Frostspark BootsFrostspark / Terraspark BootsTerraspark Boots causes both to miss you with their projectiles very often, and keeps each Twin at a stationary horizontal position most of the time, allowing you to fire continuously at it without switching your aim. Wings will help dodge each of the Twins' second phases. Using Asphalt can negate the need for Boots, while using them can allow you to avoid taking damage completely. However, try not to run too fast if you use Boots and Asphalt, as Retinazer may fall behind and despawn. Spazmatism, however, is fast enough to keep up. Regular stone blocks can be used too if you have obtained the Blessed AppleBlessed Apple.
    • The standard Boss arena of several layers of Platforms with furniture buffs makes maneuvering around easier.
      • Also, a wall on both sides of a small area can block Spazmatism's cursed fire, but be careful not to run out of time from covering behind the wall. It is helpful to have a one block hole one block up to shoot through. This is more useful if you want to try tanking the boss with the above tip of heart statues. If you can tank the hits with the help of heart statues, you can gun down Retinazer while Spazmatism is only able to charge at you.
    • A safety box in the ground isn't bad either, if you acquired the Daedalus StormbowDaedalus Stormbow. That way you could attack Retinazer while its laser can't hurt you in the box. In order to attack Spazmatism make the box one block from the surface and bring Holy ArrowHoly Arrows, the impact from the stars could hurt it. Stay close to the edge so the Cursed flames can't hurt you.
    • The player can use a Minecart TrackMinecart Track when building a sky arena to avoid The Twins' attacks whilst using a ranged weapon.

    Gearing up[]

    If a Mechanical Boss has been defeated, Life FruitLife Fruits will begin to grow in the Underground Jungle, increasing life by 5 per Life Fruit until the player reaches 500 health. It is recommended to get as much Life Fruit as possible.

    • Adamantite armorAdamantite armorAdamantite armorAdamantite armor provides the greatest overall increase to all stats. Melee and ranged users should substitute in a Frost BreastplateFrost Breastplate to increase damage output and defense without sacrificing anything important.
    • Titanium armorTitanium armorTitanium armorTitanium armor is a defensive alternative for Adamantite Armor, the Titanium BarrierTitanium Barrier / Shadow DodgeShadow Dodgebuff increases survivability.
    • Crystal Assassin armorCrystal Assassin armor has respectable defense and stat boosts, which makes this set a viable alternative to Hardmode ore sets. On Desktop version Desktop version, it provides a dash as part of its set bonus, allowing players to replace Shield of CthulhuShield of Cthulhu with another accesory.
    • Orichalcum armorOrichalcum armorOrichalcum armorOrichalcum armor provides very high critical strike chance and its set bonus can hit both eyes.
    • Palladium armorPalladium armorPalladium armorPalladium armor provides lower stat bonuses, but the Rapid HealingRapid Healing buff greatly increases natural regeneration.
    • Hallowed armorHallowed armorHallowed armorHallowed armorHallowed armor becomes a great choice if a Mechanical Boss has been defeated. The Holy ProtectionHoly Protection in the Desktop version allows the player to dodge an attack.
    • Spider armorSpider armor is the best choice for summoners who do not use whips frequently.
    • Obsidian ArmorObsidian Armor provides strong bonuses and high minion damage to summoners. The increased whip range and speed can potentially outperform Spider Armor.
    • Monk's Bushy Brow Bald Cap.pngSquire's Great Helm.pngHuntress's Wig.pngApprentice's Hat.png The armor sets available from the TavernkeepTavernkeep combine summoning with one of the other classes. This is only available if you've defeated another mechanical boss.
    • Forbidden armorForbidden armorand Frost armorFrost armor() provide weak stat bonuses, but allow you to mix different damage types. On Desktop version Desktop version, the Frost armor provides excellent stat increases as a set bonus, making it a strong alternative to Adamantite or Titanium armors.


    For Melee users
    • The Shadowflame KnifeShadowflame Knife shoots very fast and deals a lot of damage per dagger. It also inflicts ShadowflameShadowflame, which deals 15 damage per second, more than any other debuff available. If aimed right, it can manage to hit both eyes at the same time.
    • Ice SickleIce Sickle could also be used, as Spazmatism will spend most of the time behind the player, so shooting constantly backwards with the piercing projectile will hit him multiple times and deal quite reasonable damage.
      • Alternatively, Light DiscLight Discs can work too, if you already defeated The Destroyer.
    • AmarokYoyos with the Yoyo Bag can be useful.
      • If a mechanical boss has been defeated, using the YeletsYelets with the Yoyo Bag is very powerful.
    • Dao of PowDao of Pow and Drippler CripplerDrippler Crippler can be an excellent choice due to their high damage and range. However, they can be harder to acquire than other options available.
    • If Duke Fishron has been defeated, the FlaironFlairon makes the fight trivial.
    For Ranged users
    For Magic users
    For Summoners
    • The Spider StaffSpider Staff is the best summoning choice because the spiders will latch on while they change forms, dealing hundreds of damage. Note that your arena will need to include background walls to make full use of the spiders.
    • The Sanguine StaffSanguine Staff is the best summoning choice for those who don't want to make a background wall arena, its perfect tracking and high base damage makes it a powerful choice.
    • The Blade StaffBlade Staff, while weaker than the Sanguine Staff by itself, can greatly outperform it with whips that deal summon tag damage.
    • SnapthornSnapthorn's Jungle Fury buff increases the speed of whips, adding more DPS.
    • The FirecrackerFirecracker increases damage output for minions, especially with ones that have high base damage such as Sanguine Staff.
    • DurendalDurendal is a powerful choice if a mechanical boss has already been defeated, and if combined with other whips, makes it a potent weapon.
    • The Queen Spider StaffQueen Spider Staff sentry adds extra DPS, while not counting towards minion count.
    • If a Mechanical Boss has already been defeated, the Ballista CaneBallista Cane is a powerful choice when facing the Twins.


    Accessories that improve mobility are a must, since the Twins use quick attacks.

    • The Amphibian BootsAmphibian Boots, Frostspark BootsFrostspark Boots, or Terraspark BootsTerraspark Boots and Angel WingsWings are a must, especially for the Sky Bridge method. They allow the player to dodge, and also allow the player to flee temporarily if health is running low.
      • The Gelatinous Pillion can replace both the boots and the wings, as its quick vertical movement makes it excellent for dodging the flames from Spazmatism in the first stage and flying out of range in the second stage.
    • Even though it doesn't prevent Cursed Inferno, the Ankh ShieldAnkh Shield can still be used to prevent Knockback and for some useful extra defense.
    • An EmblemEmblemEmblemEmblemEmblem of the player's respective class greatly increases damage output.
    • Shield of CthulhuShield of Cthulhu's dash is essential throughout the fight.
    • Worm ScarfWorm Scarf greatly decreases damage, but is exclusive to Corruption worlds.
    • The Brain of ConfusionBrain of Confusion is very useful for Expert Mode players with Crimson, as it provides a chance to dodge an attack . It doesn't prevent getting inflicted with the Cursed InfernoCursed Inferno debuff, however.
    • The Charm of MythsCharm of Myths reduces the cooldown of Potion Sickness as well as increasing passive health regeneration.
      • It can be quickswapped in the accessory slot if using it on a vanity slot, taking advantage of its reduced Potion Sickness cooldown.
    • The Cross NecklaceCross Necklace or the Star VeilStar Veil increases invulnerability frames for a brief period upon taking damage, which can greatly mitigate alot of damage, especially from Spazmatism's charges.
    • The Moon CharmMoon Charm gives a increase to various stats, increasing survivability and damage.
    • The Magic CuffsMagic Cuffs (or Celestial CuffsCelestial Cuffs) are helpful if using Magic Weapons, but requires the user to take damage.
    • Magic QuiverMagic Quiver and its upgrades greatly increases arrow damage.
    • Pygmy NecklacePygmy Necklace adds an extra minion slot.
    • Feral ClawsFeral Claws / !!Error: Invalid EICONS input! Titan GloveTitan Glove and its upgrades enables autoswing and increases melee and whip knockback and size, making it useful for both Melee and Summoners.

    If possible, reforge all Accessories for damage, crit chance or defense bonuses. If money is no object (see Guide:Making Money), having all Accessories reforged to Warding, Lucky or Menacing provides an extra 20 defense, 20% crit chance or 20% damage (24%, since the Demon HeartDemon Heart allows you to have 6 accessories, Desktop version up to 28% in Master Mode with 7 accessory slots).



    Specific Strategies[]

    Retinazer Cheese[]

    This strategy requires you take out Spazmatism first. Once you defeat Spazmatism you need to get Retinazer into its second form. Then go inside a small box of solid blocks and use Summons (preferably with summon armor), the Meteor Staff or the Daedalus Stormbow (preferably with Holy Arrows and the Magic Quiver / its upgrades) to take down Retinazer. Because Retinazer does not charge in its second form and its lasers do not pierce blocks, you will be completely safe.

    Close-ranged Unicorn Strategy[]

    A helpful strategy is a Skybridge using a Blessed AppleBlessed Apple and any kind of yoyo (A Yoyo BagYoyo Bag is recommended) or a long range weapon. Running with the Unicorn and shooting the yoyo behind you will deal a lot of damage, and you won't get hit very much as the unicorn is slightly faster. Warning: Using this strategy may lead to the The Twins despawning if you go too fast.

    Minecart Strategy[]

    A strategy that is helpful for all classes is to use a minecart track extending as far as possible. For shorter minecart tracks, both ends can be hammered to allow the minecart to go in both directions without losing speed. As the minecart can go faster than The Twins, the player can use a long range weapon, such as a Repeater or a Yoyo (with Yoyo BagYoyo Bag) to deal damage from a relatively safe distance. Warning: Using this strategy may cause The Twins to despawn if that player travels too fast.

    Sentry Farming[]

    After gaining access to the Tier 2 equipment sold by the Tavernkeep, The Twins becomes much easier to defeat. Wearing the Squire armor and using the Ballista Cane will give the best results because of the high defense and health regeneration provided by the armor, as well as the Ballista Panic! buff doubling the firing rate. Acquiring one of the accessories dropped by the Ogre is recommended for this method. When building your arena, be sure to use platforms whenever possible to maximize the opportunities your Ballistas have to fire. Make sure that you have Heart Lanterns and Campfires set up to give yourself the most health regeneration. Having a good pair of Wings, the Cobalt ShieldCobalt Shield or its upgrades, and the Lightning BootsLightning Boots, Frostspark BootsFrostspark Boots and Terraspark BootsTerraspark Boots are recommended for maximum mobility. The Summoner EmblemSummoner Emblem will make the fight go much faster, rounding out your accessories. A few Greater Healing PotionGreater Healing Potion are all the healing you'll need in case you get backed into a tight spot. Once the Twins have been summoned in, simply kite them around your Ballistas, taking damage periodically, preferably from Retinazer's laser for minimal damage. With the best Modifiers on your gear and all the relevant buffs, the Twins will go down in two to three minutes. If you find yourself taking too much damage and needing to heal more, consider swapping out the Summoner Emblem with a Charm of MythsCharm of Myths so you can heal more often.

    Invincibility Machine []

    Warning: Some players consider invincibility machines cheating.

    After defeating a few Biome Mimics, you should have the Fetid BaghnakhsFetid Baghnakhs and the Daedalus StormbowDaedalus Stormbow. With two Target DummyTarget Dummies and a block overhead, you can make the invincibility machine. Get a Slimy SaddleSlimy Saddle and try to bounce on both dummies while keeping it rapid. After you summon the boss, use the Fetid Baghnakhs to quickly take out Spazmatism. Then use the Daedalus Stormbow to beat Retinazer.

    Note: In the 1.4 update, this glitch was changed to be much harder to pull off. Try this at your own risk, as it might not work.

    The Black Spot[]

    It is very easy to defeat The Twins with The Black Spot. The only thing you need to defeat them is high, consistent damage until dawn. Keep in mind that circling around in the skies may summon a Wyvern, so it's nice to have a weapon against segmented enemies (such as the Medusa Head).

    Note: The Black Spot was nerfed to be slightly slower in 1.4.1, which may result in taking more damage than intended.

    Bouncing Strategy []

    It is very effective if you are able to keep The Twins low to the ground to bounce on them repeatedly using a Slimy SaddleSlimy Saddle. It works especially well to pair this with the Meteor StaffMeteor Staff, raining meteors down on whichever eye you happen to be bouncing on.