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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Status: Subject to revision (This Guide does not meet certain quality standards and may be heavily outdated.)
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  • Skeletron Prime Trophy.png"The air is getting colder around you..."Skeletron Prime Trophy.png

    Skeletron Prime is the Hardmode version of Skeletron. It is one of the three Mechanical bosses, alongside The Destroyer and The Twins. It can deal a lot of damage with its four limbs, and its high health and defense allow it to take a lot of punishment. The limbs have the added effect of blocking non-piercing shots aimed at its head.

    Skeletron Prime
    Skeletron Prime.pngOld-gen console version and Nintendo 3DS version
    Map Icon Skeletron Prime.png
    Map Icon
    Classic mode icon.png Classic
    Expert mode icon.png Expert
    Master mode icon.png Master
    AI TypeSkeletron Prime Head AI
    94158238 (while spinning) [1]
    Max Life28000/42000/53550
    48 (while spinning) [1]
    KB Resist100%
    Immune toPenetratedConfusedTentacle SpikePoisoned

    Spawning Conditions[]

    Skeletron Prime can be spawned by fulfilling any of these conditions:

    • After smashing a Demon AltarDemon/Crimson AltarCrimson Altar, it will have a 10% chance of appearing when night falls, until it is defeated for the first time. This condition is shared with the rest of the trio, so there's a chance that the Destroyer or Twins will spawn instead.
    • Use a Mechanical SkullMechanical Skull at night.

    Either way, it must then be defeated before all involved players die, or before daybreak, whichever comes first.

    The Fight[]

    Skeletron Prime is a flying boss that consists of five parts:

    • Prime Saw, a melee arm, with 9000 health.
    • Prime Vice, a melee arm, with 9000 health.
    • Prime Laser, a ranged arm that fires lasers, with 6000 health.
    • Prime Cannon, a ranged arm that fires grenades, with 7000 health.
    • Skeletron Prime, the head, with 28000 health.

    Killing the head will count as a victory, and any remaining limbs will be destroyed.

    Each limb has a unique attack pattern, listed below. Although killing the limbs is not necessary, they can block attacks to the head (especially Prime Saw and Prime Vice), and destroying them makes the fight much easier. It is safest to take out the most dangerous limbs at the beginning, as the fight gets significantly easier without their interference.

    Prime Saw[]

    Prime Saw is one of the two melee limbs. It lunges at the player, dealing a lot of damage if its attack connects. However, compared to the other limbs, the Saw is not as aggressive, and has a predictable pattern. Accordingly, it is a lesser threat despite the high damage, and a low priority.

    Prime Vice[]

    Prime Vice is one of the two melee limbs. Compared to the Saw, it does less damage, but it is more aggressive. It lunges at the player, attacking many times before retracting.

    Although its pattern can be somewhat predictable, its behavior when Prime is enraged makes it a very dangerous limb, capable of dealing significant damage if the player is not careful.

    Prime Laser[]

    Prime Laser is one of the ranged limbs. It will consistently remain above the player, firing lasers at a moderate rate. Its shots deal significant damage and it is Prime's most threatening limb in Expert mode. The laser starts shooting much faster when Prime enters its "enraged" state, making it an even bigger problem.

    Its damaging, fast, and accurate shots arguably make it Prime's most dangerous limb. Because of this and its relatively low health, it should ideally be destroyed before the others.

    Prime Cannon[]

    Prime Cannon is the other ranged limb. It shoots bombs that do not destroy tiles or deal contact damage. The bombs also do not collide with platforms / Planter Boxes. This means that if the player fights in an arena, the Cannon will very rarely do any damage since the bombs only explode when they land on a solid block.(note: if you destroy every second tile of the platform to save up platform blocks, the platform will be considered a solid block and the bombs will explode upon contact)

    The inaccuracy and relatively low damage of the bombs makes the Cannon significantly less threatening than any of the other limbs. It can safely be ignored in favor of more dangerous targets.

    However, it is important to note that on the secret seed For the worthy, the bombs that the Prime Cannon shoots will destroy tiles. Failure to destroy this limb early could result in any arena prepared to be wrecked, making the fight much more difficult.

    Skeletron Prime[]

    Skeletron Prime "proper" is the head, which must be destroyed to win. Skeletron Prime will try to float above the player at all times. It will close in to do its spinning attack, which doubles its attack and defense and empowers its other limbs, making them attack more frequently. Once it finishes spinning, it will retreat again.

    Like Skeletron, if the head is not destroyed by morning, it will be locked in its spinning attack, gain a speed increase, and its attack and defense will increase to near-unbeatable levels. In this state, a single hit will kill the player, while the head will only take one damage per hit and two damage per critical hit.

    Killing the head is a lot easier once some of its limbs are down, especially the Vice and the Laser. Focusing only on the head still works should the player wish to end the fight as soon as possible, but usually it is safer to focus on the arms first.

    Moving diagonally will make dodging the spinning head easier, as players can move faster in diagonal directions than in others.

    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.
    • When using Summon weapons, it is recommended to use the targeting function to focus one arm at a time and reduce the threat Skeletron Prime poses. Simply right-click near one of the weapons to target it and your minions will prioritize that arm.
    • All classes should note that Frostburn is one of the few available debuffs that this boss is not immune to, so any weapon providing it or the Frost armor will be especially handy. If available, Ichor is also useful to cut into the boss's high defense.
    • If the player gets too far from the head while it is not spinning, it will fly back to the player extremely quickly, which can be difficult to dodge. Keep within a reasonable distance.
    • Skeletron Prime is a reliable choice as a first mechanical boss to fight, as it has much lower damage output than the other two. If properly equipped, the biggest challenge will be ending the fight before dawn.

    Terrain preparation[]

    As with all bosses, an arena made out of Wooden Platform or Minecart Track greatly increases your mobility, and it will also moot the Prime Cannon. You will want several rows of Platforms, each around 50 or so blocks long. The platforms should be suspended off the ground to prevent the Prime Cannon's grenades from detonating too close to you. A solid ceiling should be avoided since Skeletron Prime will often retreat a fair distance when not using his spinning attack. It is also best to use frozen slime blocks as they keep the mobility of any speed enhancements.

    Gearing up[]


    • Adamantite armorAdamantite armorAdamantite armorAdamantite armor provides the overall greatest increase to all stats.
    • Titanium armorTitanium armorTitanium armorTitanium armor is a great choice due to its high stats. It also provides the Titanium BarrierTitanium Barrier / Shadow DodgeShadow Dodge buff.
    • Crystal Assassin armorCrystal Assassin armor's respectable defense, stat boosts and dash ability can make it a viable alternative to Hardmode ore sets.
    • Orichalcum armorOrichalcum armorOrichalcum armorOrichalcum armor provides very high critical strike chance and its set bonus can hit multiple parts.
    • Palladium armorPalladium armorPalladium armorPalladium armor provides lower stat bonuses, but the Rapid HealingRapid Healing greatly increases natural regeneration.
    • Hallowed armorHallowed armorHallowed armorHallowed armor becomes a great choice if you have already defeated a Mechanical Boss, since it provides the Holy ProtectionHoly Protection buff.
    • Spider armorSpider armor is the most practical choice for Summoners. However, for Blade Staff users, the Obsidian Armor remains extremely viable well into Hardmode due its set bonuses applying to whips.
    • Monk's Bushy Brow Bald Cap.pngSquire's Great Helm.pngHuntress's Wig.pngApprentice's Hat.png The armor sets available from the Tavernkeep combine summoning with one of the other classes. This is only available if you've already defeated one Mechanical Boss.
    • Frost armorFrost armor and Forbidden armorForbidden armor provide weak stat bonuses, but allow you to mix different damage types.


    For melee users[]
    For ranged users[]
    For magic users[]
    • You can use the Crystal SerpentCrystal Serpent which functions similarly to Crystal Bullets and deals high damage.
    • The Sky FractureSky Fracture is just as strong.
    • The Meteor StaffMeteor Staff is powerful and easy to craft, provided you have some leftover Meteorite Bars from Pre-Hardmode.
    • The Golden ShowerGolden Shower deals little damage but inflicts the Ichor (debuff)Ichor debuff, allowing your other weapons to deal even more damage.
    • The Flower of FrostFlower of Frost is a decent weapon that inflicts Frostburn, which Skeletron Prime is not immune to.
    • The Rainbow RodRainbow Rod is available if you have defeated The Twins previously. The projectile is homing and piercing, meaning it is all but guaranteed to hit three sections of the boss with each cast while at the same time allowing you to focus on dodging.
    • Beating a Hardmode goblin army can provide access to the Shadowflame Hex DollShadowflame Hex Doll, dropped by the Goblin Summoner. The scattering attack can hit multiple limbs and the head rapidly, dealing substantial damage in little time.
    For summoners []
    • The Sanguine StaffSanguine Staff is an extremely good summon weapon, due to its perfect tracking and high damage.
    • The Blade StaffBlade Staff is also an extremely viable option due to its fast tracking and insanely fast attack speed. As Skeletron Prime is vulnerable to Ichor, Ichor Flasks can greatly increase the effectiveness of the Blades, as together they ignore 40 defense (45 on Mobile). Whips can boost its damage further.
    • If you have already defeated The Twins, you can use the Optic StaffOptic Staff to summon miniature versions of them.
    • The Spider StaffSpider Staff is very useful for defeating the laser and cannon, as they don't move much and allow the spiders to cling for longer.
    • The Queen Spider StaffQueen Spider Staff is a great choice if you tend to remain in one area the entire battle.
    • Whips, especially the Cool WhipCool Whip with its armor-ignoring snowflake projectile, are effective at dealing damage to several body parts at once or empowering your minions.
    • The DurendalDurendal is preferred if at least one mechanical boss has been defeated prior, as it provides Summon Tag damage.


    • Accessories that increase your mobility such as the Lightning BootsLightning Boots or Wings are a must.
    • An Emblem for your class can increase your damage output significantly.
    • The Frog LegFrog Leg ( and its upgrades) makes all wings significantly faster, which helps when dodging its attacks.
    • The Charm of MythsCharm of Myths increases your base health regeneration and reduces the cooldown on potions, making it a good choice if you have trouble dodging its attacks.
    • The Cobalt ShieldCobalt Shield or its upgrades make you immune to knockback, preventing Skeletron Prime from knocking you around.
    • The Expert-exclusive Shield of CthulhuShield of Cthulhu can greatly increase your mobility as well as provide some extra defense.
    • The Expert-exclusive Worm ScarfWorm Scarf will reduce damage taken, making it a powerful choice.
    • On Desktop version Desktop, Console version Console, Mobile version Mobile, and Nintendo Switch version Switch, the Expert-exclusive Brain of ConfusionBrain of Confusion has a chance to dodge an attack, providing the player with a useful Cerebral MindtrickCerebral Mindtrick buff.


    Mixed strategies[]

    • It is possible to defeat Skeletron Prime by continuous attacks alternating the Megashark and a full stack of Light Discs, while wearing a full set of Palladium armor. However, this is likely to cut the time limit very close, and whichever headpiece you choose, only one of your weapons will get a class bonus. In general, Hardmode fights reward class purity.
    • On !!Error: {{eversions}}: No valid parameters were entered!, it is very easy to defeat Skeletron Prime with The Black Spot, as it is able to move faster than the boss. The only thing you need is stable and high enough damage to win before dawn.
    • An effective way to avoid his spinning head attack is to use a Gelatinous PillionGelatinous Pillion and jump on top of his head with the mount. You can even use this to your advantage to get extra hits as it keeps bouncing you up.
    1. 1.0 1.1 Information taken from the Desktop version Desktop source code, method AI() in Terraria.NPC.cs (under aiStyle == 32) There may be inaccuracies, as the current Desktop version Desktop version is