Skeletron Prime

Skeletron Prime

Map icon

Statistics

Type	Boss
Environment	Surface
Damage	50 / 85 / 102 / 119 / 153 (Contact) 100 / 170 / 204 / 238 / 306 (Spin) 124 / 136 / 186 (Death Laser) 124 / 136 / 186 (Skull) 148 / 160 / 222 (Rocket, Missile)
Max Life	28,000 / 42,000 / 60,900 / 53,550 / 64,260
Defense	24 (+8 per arm alive) (Doubled if spinning)
DR	20%
KB Resist	100%
Inflicts debuff	On Fire! 100% chance
Debuff duration	4 seconds (Rocket, Laser)
Debuff tooltip	Slowly losing life
Immune to

Resistances

Cold	-
Water	-
Sickness	Resistant
Electricity	Vulnerable
Heat	-

Drops

Coins	40

• Item (Quantity)Rate
• Soul of Fright (20-40 / 25-40 )
  100%
• Hallowed Bar (15-30 / 20-35 )
  100% (After defeating The Twins and The Destroyer)
• Mechanical Battery Piece
  100%
• Greater Healing Potion (5-15)
  100%
• Skeletron Prime Mask
  14.29%
• Skeletron Prime Trophy
  10%
• Thank You
  1%
• Skeletron Prime (Lore)(Only on first kill)
  100%
• Treasure Bag(Skeletron Prime)
  100%
• Robotic Skull(In Master or Revengeance Mode only)
  25% / 25%
• Skeletron Prime Relic(In Master or Revengeance Mode only)
  100% / 100%

Sounds

Hurt

Killed

Spinning

Homing Skull

If you were looking for Skeletron Prime on the vanilla wiki, click here.

"...he crafted a visage so grim, it evoked oblivion itself."

Skeletron Prime is a Hardmode mechanical boss which is essentially a more difficult version of Skeletron.

While in Revengeance and Death Mode, Skeletron Prime gains various projectile changes to both the head and limbs, and the boss gets an overall stats buff. The head gains more attacks and behaviors as the limbs are killed.

Spawn

Skeletron Prime can be manually summoned using a Mechanical Skull at night (7:30 PM to 4:30 AM) in any biome. It can also spawn naturally upon dusk with a chance of 10% once a Demon or Crimson Altar has been smashed, as long as it has not yet been defeated in the current world. If spawning naturally, its arrival is announced by the status message: "The air is getting colder around you..."

Arms

Prime Cannon

Statistics

Type	Boss
Environment	Surface
Damage	30 / 51 / 68 / 85 / 102 (Contact) 80 / 160 / 240 (Bomb) 148 / 160 / 222 (Rocket)
Max Life	7000 / 10,500 / 6825 / 13,386 / 8700
Defense	23
DR	20%
KB Resist	100%
Inflicts debuff	On Fire! 100% chance
Debuff duration	4 seconds (Rocket)
Debuff tooltip	Slowly losing life
Immune to

Resistances

Cold	-
Water	-
Sickness	Resistant
Electricity	Vulnerable
Heat	-

Sounds

Hurt

Killed

Bomb launch

Bomb explosion

Rockets

Prime Saw

Statistics

Type	Boss
Environment	Surface
Damage	60 / 102 / 136 / 153 / 204
Max Life	9000 / 13,500 / 8775 / 17,211 / 11,187
Defense	38
DR	20%
KB Resist	100%
Immune to

Resistances

Cold	-
Water	-
Sickness	Resistant
Electricity	Vulnerable
Heat	-

Sounds

Hurt

Killed

Prime Vice

Statistics

Type	Boss
Environment	Surface
Damage	60 / 102 / 136 / 153 / 204
Max Life	9000 / 13,500 / 8775 / 17,211 / 11,187
Defense	34
DR	20%
KB Resist	100%
Immune to

Resistances

Cold	-
Water	-
Sickness	Resistant
Electricity	Vulnerable
Heat	-

Sounds

Hurt

Killed

Prime Laser

Statistics

Type	Boss
Environment	Surface
Damage	30 / 51 / 68 / 85 / 102 (Contact) 50 / 100 / 124 / 136 / 150 / 186 (Death Laser)
Max Life	6000 / 9000 / 5850 / 11,475 / 7458
Defense	20
DR	20%
KB Resist	100%
Inflicts debuff	On Fire! 100% chance
Debuff duration	4 seconds (Laser)
Debuff tooltip	Slowly losing life
Immune to

Resistances

Cold	-
Water	-
Sickness	Resistant
Electricity	Vulnerable
Heat	-

Sounds

Hurt

Killed

Death Laser

Behavior

The Prime Laser and Cannon move faster.

In Revengeance Mode

The head receives a defense buff of 8 per arm alive, and various changes ensue when the arms are killed. If the head reaches 66% health at any time, all the limbs will die. The head's spin attack will not happen while any arms are alive and is significantly faster. Its defense doubles while spinning, regardless of difficulty. The head gains speed as it loses health.

The changes to the arms are as follows:

Prime Cannon

• Fires rockets instead of bombs. Alternates between firing single rockets and three rockets at once.
• Rockets have a weak homing effect shortly after being fired.
• Alternates attacks with the Prime Laser.

Prime Laser

• No longer fires lasers in a cone.
• Lasers now start moving slower but quickly accelerate over time.
• Alternates between firing single lasers and laser circles.
• Alternates attacks with the Prime Cannon.

Prime Saw and Prime Vice

• More aggressive AI.
• Arms stay tighter to the head.

As limbs die, the other limbs gain increased movement and attack speed. When all the limbs are killed, the head will gain an attack where it moves in a tight circle and fires cursed skull projectiles similar to Skeletron, which it alternates with its spin attack. When the head reaches 40% health, it will begin firing laser circles during its spinning attack. When the head reaches 20% health, it gains a third attack where it fires a barrage of 10 homing missiles. It will cycle through these, starting with the circling attack, its spinning charge, and then its missiles. If day comes and Skeletron Prime is still alive, its current health will increase to 300 if it is below that.

In Death Mode

• Fires skulls more frequently when spinning.
• The head gains a speed boost if gravity is inverted.
• Hands and head increase in velocity and acceleration as their health decreases.

During the Boss Rush

• Max health increased to 1,100,000 / 1,650,000 / 1,980,000 .
• Sets the time to 7:30pm.
• Moves much faster.
• Cannon shoots out 5 rockets instead of 3.
• Head occasionally fires homing Martian Rockets.
• Both the head and the laser shoot out more lasers and attack much more frequently.
• Spins for less time as health drops.

Aftermath

• If the Early Hardmode Progression Rework option is enabled, new ores will generate in the Underground and Cavern layers:
  • If Skeletron Prime is the first mechanical boss to be defeated, Mythril and Orichalcum Ore will be generated.
  • If Skeletron Prime is the second mechanical boss to be defeated, Adamantite and Titanium Ore will be generated.
  • If Skeletron Prime is the third mechanical boss to be defeated, Hallowed Ore will be generated in the Underground Hallow biome.
• The Bandit will begin selling the Momentum Capacitor if The Twins and The Destroyer have also been defeated.
• The Drunk Princess will begin selling Vodka, Screwdriver and White Wine if The Twins and The Destroyer have also been defeated.
• The Archmage will begin selling the Arctic Bear Paw, Frosty Flare, Cryophobia, and Cryogenic Staff if The Twins and The Destroyer have also been defeated.

Terrain Preparation

Due to Skeletron Prime's diverse attacks, it is recommended that the player makes a decently sized arena with about 20-25 gaps between each platform to allow easy movement without getting stuck between each floor. The arena should be big enough to allow circling Skeletron Prime in its later phases, during its cursed skull attack, and to allow an easy way to run away from its deadly spin charge that spews out lasers.

Gearing Up

For a Normal and Expert mode guide to Skeletron Prime, see Skeletron Prime on the vanilla wiki.

Armor

• Due to the hardmode ore rework, the best available armor depends on how many other mechs have been defeated.
  • If no other mechs have been defeated, Palladium armor is a strong option providing health regeneration.
  • If one other mech has been defeated, Orichalcum armor provides extra DPS while Mythril armor has all-around stat bonuses
  • If two mechs have been defeated, Titanium armor has a strong set bonus. If Cryogen has also been defeated, Daedalus armor is among the strongest available. For mixed classes, Frost armor and Forbidden armor give the most flexibility.
• Titan Heart armor is always available for Rogues.
• Mollusk armor has very high stats but makes you quite slow.
• Spider armor is a powerful summoner armor available from the start of hardmode.

Accessories

• The best wings available before Mythril Ore is available are Fairy Wings (with their health boost) or Leaf Wings with their flight time.
  • The Aero Stone, Grand Gelatin, or Frog Leg will improve the usefulness of wings even further and improve vertical motion.
• Frostspark Boots or their predecessor, Lightning Boots, can aid in movement.
• Dashing can help avoid attacks.
  • For horizontal dashes, use Evasion Scarf or the Shield of Cthulhu.
  • For vertical movement, the Slimy Saddle or the Gelatinous Pillion allows you to drop quickly.
• Using your class-specific emblem is highly recommended for an extra damage boost. Calamity also has an exclusive emblem for the Rogue class.
• The Magic Quiver works well in maintaining ammo as well as greatly improving the firepower of bows, but it is not required.
• Magic players can make use of the Celestial Cuffs and/or Mana Flower along with Mana Potions to recover their mana during the fight, as well as using the Mana Polarizer to recover lost health.
• Summoners can boost their minion damage and defensive stats with the Spirit Glyph.
• Rogue users will find the Raider's Talisman useful to boost their damage output.

Weapons

Melee

• The Caustic Edge is a great pick for melee users due to its easy-to-aim projectile.

Ranged

• The Dart Pistol or Dart Rifle can be great choices for Skeletron Prime.
• The Frostbite Blaster does excellent damage and can hit multiple parts at once.
• The Needler is another viable option that is quite easy to get your hands on.
• The Cursed Capper is a weaker option but very easy to obtain.

Magic

• The SHPC's left-click attack can damage many parts of Skeletron Prime at once, while the right-click attack is better for the head.
• Poseidon does good multi-target homing damage.
• Frigidflash Bolt is a bit weaker but can do good damage.

Summoning

• The Shellfish Staff is great for Skeletron Prime due to its high debuff damage.
• The Black Hawk Remote is also great due to its ability to lock onto targets.

Rogue

• The Prismalline is a great choice due to its many powerful projectiles.
• The Gacruxian Mollusk's homing capabilities help in this fight.
• If The Twins were defeated previously, the Frequency Manipulator has both homing and piercing properties.

All classes

• The Golden Shower is very helpful for increasing DPS and getting around Skeletron Prime's high defense.

Tips

• The player should be aware of the hands and remember that for each arm destroyed, the rest get faster.
• Good area-of-effect damage works well for the limbs, and mobility should be prioritized.
• Once all arms are destroyed, the player should be aware of Skeletron Prime's spin attack, which can be devastating if caught inside.
• During the cursed skull attack, a good strategy is to circle Skeletron Prime from afar to avoid its homing skulls.

History

edit

These history sections are still a work-in-progress, and may not yet contain changes relevant to the current version of the Calamity Mod.

• 2.0.2.002: Head now properly displays vanilla debuff colors and Hunter Potion effects in Revengeance Mode or Death Mode.

• 2.0.2.001: Buffed Boss Rush health from 150,000 / 225,000 / 270,000 / 286,875 / 344,250 to 160,000 / 240,000 / 288,000 / 306,000 / 367,200 .

• 2.0.1.003: Buffed Boss Rush health from 110,000 / 165,000 / 198,000 / 210,375 / 252,450 to 150,000 / 225,000 / 270,000 / 286,875 / 344,250 .

• 2.0.1.001:
  • No longer flings its Laser and Cannon arms at the player, and no longer fires a barrage of Rockets or a ring of Laser projectiles from its head while all of its arms are destroyed in Revengeance and Death Mode.
  • Now enters its spin phase after 1.5 seconds instead of 5 in Revengeance and Death Mode.

• 1.5.1.003:
  • Now drops 40 .
  • No longer gains additional defense while its limbs are alive.
  • Now enters phase 2 at 50% health instead of 66%, and phase 3 at 25% health instead of 33% on Revengeance Mode and above.

• 1.5.1.001:
  • Buffed Head skull damage from 44 / 88 / 112 / 124 to 50 / 100 / 124 / 136 .
  • Buffed Head Missile and Rocket damage from 54 / 108 / 132 / 144 to 60 / 120 / 148 / 160 .
  • Buffed Prime Cannon Rocket damage from 54 / 108 / 132 / 144 to 60 / 120 / 148 / 160 .
  • Buffed Prime Saw damage from 60 / 102 / 119 / 136 to 60 / 102 / 136 / 153 .
  • Buffed Prime Vice damage from 60 / 102 / 119 / 136 to 60 / 102 / 136 / 153 .
  • Revengeance Mode changes:
    • Laser and rocket attacks from the head now only occur after all arms are defeated, instead of after Laser and Cannon arms respectively.
    • Rockets are fired 6.67% less often below 33% health.
    • Increased spin duration from 3 / 2-3 seconds to 4 / 3-4 seconds when below 33% health.
    • Decreased the head's movement speed during the spin attack.
    • Decreased the head's laser and rocket projectile speeds.
  • All parts are now vulnerable to electricity debuffs but resistant to sickness debuffs.
  • Now drops Mechanical Battery Piece regardless of world difficulty.

• 1.5.0.003: Fixed an issue that prevented flaming skull projectiles from dealing damage on Revengeance Mode.

• 1.5.0.001:
  • Nerfed Boss Rush health from 1,100,000 / 1,650,000 / 1,980,000 to 110,000 / 165,000 / 198,000 .
  • No longer enrages if the player flips gravity.
  • Now slows down by 50% while using a true melee weapon in Revengeance Mode.
  • Laser pattern in Revengeance Mode now uses a set pattern.

• 1.4.5.004:
  • Nerfed Head health in Revengeance Mode from 60,900 to 50,400 .
  • Nerfed Head health when summoned by Draedon's Remote in Revengeance Mode from 79,800 to 60,900 .
  • Decreased rocket velocity.
  • Buffed defense boost for each limb alive from 10 / 15 to 20 .
  • Prime Saw, Prime Vice and Head no longer inflict Bleeding in Revengeance Mode.
  • Fixed an issue that prevented it from releasing homing skulls while spinning in Death Mode.

• 1.4.5.003:
  • Nerfed Prime Saw and Vice health from 13,500 to 8775 , Prime Laser health from 9000 to 5850 , and Prime Cannon health from 10,500 to 6825 in Revengeance Mode.
    • Decreased Draedon's Remote limbs health modifier from 1.05x to 0.8x.
  • Head and all limbs will increase in velocity and acceleration as its health decreases in Death Mode.
  • Fixed a bug that caused it to move slower than intended while performing its head-spin.

• 1.4.5.002:
  • Limbs cannot deal damage for 3 seconds after spawning.
  • Rockets in Revengeance Mode are now slightly slower.
  • Draedon's Remote variant now drops Dubious Plating and Mysterious Circuitry.

• 1.4.5.001: Removed Probes from the fight in Revengeance and Death Mode.

• 1.4.4.004:
  • Now gains 8 defense per limb alive in Revengeance Mode instead of 9999.
  • In Revengeance Mode, if the head's health is reduced to 66%, all limbs are instantly killed and it moves to the next phase.

• 1.4.3.001:
  • Nerfed head contact damage from 47 / 79 / 98 / 113 to 47 / 79 / 90 / 97 .
  • Nerfed head spin damage from 94 / 158 / 197 / 227 to 94 / 158 / 181 / 195 .
  • Nerfed Prime Saw's damage from 56 / 95 / 118 / 136 to 56 / 95 / 114 / 125 .
  • Nerfed Prime Vice's damage from 52 / 88 / 110 / 126 to 52 / 88 / 105 / 116 .
  • Nerfed Prime Laser's contact damage from 29 / 49 / 61 / 70 to 29 / 49 / 58 / 64 .
  • Nerfed Prime Cannon's contact damage from 30 / 51 / 63 / 73 to 30 / 51 / 61 / 67 .
  • Nerfed skull projectile damage from 112 / 128 to 112 / 124 .
  • Nerfed missile and homing rocket damage from 132 / 151 to 132 / 144 .
  • Nerfed laser damage from 50 / 100 / 124 / 142 to 50 / 100 / 124 / 136 .
  • Nerfed health in Revengeance Mode from 50,400 to 48,300 and damage reduction from 25% to 20%.
  • Nerfed health modifier using Draedon's Remote from 1.6x to 1.45x.
  • Increased the maximum speed in Revengeance Mode but defeating limbs now decreases maximum speed instead of increasing it.
  • Decreased the maximum speed of all limbs in Revengeance Mode.
  • Nerfed Prime Saw and Prime Vice damage reduction from 25% to 20%.
  • Prime Saw and Prime Vice now inflict Marked for 3 seconds.
  • Death Mode changes:
    • Transitions into Phase 2 and 3 when all limbs are defeated instead of below 66% and 33% health.
    • Decreased head, Prime Laser, and Prime Cannon projectile firing rate.
    • Decreased head spin duration.
    • Decreased Prime Saw and Prime Vice charge frequency.

• 1.4.2.106:
  • Buffed Boss Rush health from 980,000 to 1,100,000.
  • Revengeance Mode head no longer fires homing skulls while arms are alive.
  • Revengeance Mode Prime Laser and Prime Cannon now move more quickly.

• 1.4.2.105:
  • Revengeance Mode changes:
    • Changed head's health modifier from 1.15x / 1.5x to 1.2x / 1.45x .
    • Nerfed limbs' health modifier from 1.1x to 0.9x .
    • Nerfed limbs' health modifier when Draedon's Remote is used from 1.15x / 1.45x to 1.05x / 1.15x .
    • Arms have less health, but the head has more health.
    • Will no longer spawn homing skulls or Probes if the player is too close to its head.
    • Now flies up and down more aggressively the less arms it has left.
    • Glides further left and right to make the melee arms more threatening.
    • Will only heal up to 300 health when enraged at sunrise. Healing will only occur when below half health.
    • Lasers now inflict On Fire! for 4 seconds instead of 3.
    • Homing Skulls now inflict Weak for 3 seconds instead of 2.

• 1.4.2.104:
  • Buffed Boss Rush health from 780,000 to 980,000.
    • Buffed Prime Cannon's Boss Rush health from 350,000 to 450,000.
    • Buffed Prime Vice's Boss Rush health from 440,000 to 540,000.
    • Buffed Prime Laser's Boss Rush health from 280,000 to 380,000.
  • Arms now have their own health modifier of 1.15x / 1.45x instead of sharing theirs with the head.
  • Can now drop Burden Breaker while enraged in Revengeance Mode.
  • Reworked Revengeance Mode AI:
    • Head is almost immune to damage until all four arms are killed, but the arms have reduced health.
    • The head gains new abilities each time an arm is killed and goes berserk when all four arms are slain.
    • Actively attacks the player with two arms at once, and switches which arms it is using over time.
    • Head and melee arms inflict Bleeding on contact.
    • Removed random spread from Prime Laser's lasers.
    • Changed the pattern of its laser ring.
    • Prime Cannon can now fire rockets.
    • Prime Vice moves less erratically.

• 1.4.2.103: Nerfed head and limb health modifier from 1.6x / 2.9x to 1.15x / 1.5x .

• 1.4.2.102: Prime Laser no longer has decreased health in Death Mode.

• 1.4.2.004: Now enrages if the player has the Gravitation Potion's effects active in Revengeance Mode.

• 1.4.2.001:
  • Nerfed head, cannon, vice, and saw's health modifiers from 1.5x / 2.15x to 1.25x / 1.9x .
  • Nerfed Boss Rush health from 1,560,000 to 780,000.
  • Nerfed Prime Cannon's Boss Rush health from 700,000 to 350,000.
  • Nerfed Prime Vice's Boss Rush health from 880,000 to 440,000.
  • Nerfed Prime Saw's Boss Rush health from 900,000 to 450,000.
  • Nerfed Prime Laser's Boss Rush health from 560,000 to 280,000.

• 1.4.1.002: Decreased speed in Revengeance Mode.

• 1.4.1.001:
  • Buffed Boss Rush health from 780,000 to 1,560,000.
  • Buffed Prime Cannon's Boss Rush health from 350,000 to 700,000.
  • Buffed Prime Vice's Boss Rush health from 420,000 to 880,000.
  • Buffed Prime Saw's Boss Rush health from 280,000 to 560,000.
  • Buffed Prime Laser's Boss Rush health from 280,000 to 560,000.
  • Buffed Boss Rush damage modifier from 2x to 2.5x.
  • Skeletron Prime, Prime Vice, and Prime Saw now inflict Bleeding in Revengeance Mode.
  • Revengeance Mode skulls now inflict Weak.
  • Lasers now inflict On Fire! in Revengeance Mode.
  • Skeletron Prime and its limbs no longer take 50% damage from Crystal Bullet shards and Holy Arrow stars.

• 1.4.0.001:
  • Buffed health modifier from 1.4x / 2.05x to 1.5x / 2.15x .
  • Buffed Draedon's Remote variant's health modifier from 1.5x / 2.8x to 1.6x / 2.9x .
  • Buffed Prime Laser's health modifier in Death Mode from 0.1x to 0.15x .
  • Buffed Prime Laser's Draedon's Remote variant's health modifier in Death Mode from 1.4x to 1.5x .
  • Nerfed Prime Cannon and Prime Laser damage reduction from 25% to 20%.
  • Nerfed Head, Prime Saw, and Prime Vice damage reduction from 30% to 25%.
  • Lowered projectile fire rates in Revengeance Mode.

• 1.3.4.101:
  • Buffed health modifier from 1.35x / 2x to 1.4x / 2.05x .
  • Nerfed Head damage reduction from 50% to 30%.

• 1.3.4.001:
  • Changed health modifier for the head, cannon, saw, and vice from 1.1x / 2.2x to 1.35x / 2x .
  • Can now do its laser ring attack in Death Mode regardless of whether or not Prime Laser is alive.

• 1.3.3.001: Limbs are now affected by the early Hardmode health and damage nerfs.

• 1.2.4.101:
  • Buffed Prime Laser's Death Mode health modifier from 1.2x to 2.2x .
  • Nerfed skull projectile damage from 35 / 70 / 87 to 32 / 64 / 80 .
  • Nerfed head laser damage from 30 / 60 / 75 to 27 / 54 / 67 .
  • Nerfed missile damage from 40 / 80 / 100 to 32 / 64 / 80 .

• 1.2.4.002:
  • Nerfed health modifier from 1.15x to 1.1x.
  • Nerfed Prime Laser's health modifier from 1.3x to 1.2x.

• 1.2.3.005: Head now fires bursts of lasers going in random directions if Prime Laser is killed in Death Mode.

• 1.2.3.002: Now gains a 1.3x health modifier in Death Mode.

• 1.2.0.002:
  • Prime Saw and Prime Vice now inflict Marked for Death for 3 seconds in Revengeance Mode.
  • No longer spins more often if the player has high Stress.
  • Prime Cannon no longer fires more often if the player has high Stress.

• 1.2.0.001:
  • Now gains a 1.15x health modifier in Revengeance Mode.
  • Increased overall speed, but now speeds up at lower amounts of health.
  • Now has a 2% chance to drop Laudanum or Stress Pills in Revengeance Mode.

• 1.1.7.801: The status message "A blood red inferno lingers in the night..." now appears when defeated.