Skeletron Prime
Type | Boss |
---|---|
Environment | Surface |
Damage | 50 / 85 / 102 / 119 / 153 (Contact) 100 / 170 / 204 / 238 / 306 (Spin) 124 / 140 / 150 (Death Laser) 124 / 140 / 150 (Skull) 148 / 176 / 222 (Rocket, Missile) |
Max Life | 28,000 / 42,000 / 60,900 / 53,550 / 91,035 |
Defense | 24 (+8 per arm alive) (Doubled if spinning) |
DR | 20% |
KB Resist | 100% |
Inflicts debuff | On Fire! 100% chance |
Debuff duration | 3 seconds (Rocket, Laser) |
Debuff tooltip | Slowly losing life |
Inflicts debuff | Bleeding 100% chance |
Debuff duration | 5 seconds (Spinning) |
Debuff tooltip | Cannot regenerate life |
Immune to |
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)
- 100%
- Greater Healing Potion (5-15)100%
- 14.29%
- 10%
- Skeletron Prime (Lore)(Only on first kill)100%
- Treasure Bag(Skeletron Prime)
- Robotic Skull(In Master or Revengeance Mode only)
- Skeletron Prime Relic(In Master or Revengeance Mode only)
- 1%
- 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 boss that can be fought anywhere on the surface during the night.
While in Revengeance and Death Mode, Skeletron Prime gains various projectile changes to both the head and arms, and the boss gets an overall stats buff. The head gains more attacks and behaviors as the arms are killed.
Spawn
Skeletron Prime can be manually summoned using a Mechanical Skull during the night. 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
Type | Boss |
---|---|
Environment | Surface |
Damage | 0 (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 | 3 seconds (Bomb) 3 seconds (Rocket) |
Debuff tooltip | Slowly losing life |
Immune to |
Type | Boss |
---|---|
Environment | Surface |
Damage | 35 / 51 / 68 / 85 / 129 (Contact) 70 / 102 / 136 / 170 / 255 (Swipe) |
Max Life | 9000 / 13,500 / 8775 / 17,211 / 11,187 |
Defense | 38 |
DR | 20% |
KB Resist | 100% |
Inflicts debuff | Bleeding 100% chance |
Debuff duration | 3 seconds |
Debuff tooltip | Cannot regenerate life |
Immune to |
Type | Boss |
---|---|
Environment | Surface |
Damage | 0 (Contact) 70 / 102 / 136 / 170 / 255 (Swiping) |
Max Life | 9000 / 13,500 / 8775 / 17,211 / 11,187 |
Defense | 34 |
DR | 20% |
KB Resist | 100% |
Immune to |
Type | Boss |
---|---|
Environment | Surface |
Damage | 0 (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 | 3 seconds (Laser) |
Debuff tooltip | Slowly losing life |
Immune to |
Behavior
The Prime Laser and Cannon move faster.
In Revengeance Mode
If Skeletron Prime is fought during the day and is still alive, it will become enraged, and its current health will increase to 300 if it is below that.
- Head gains 8 defense for each arm alive and various changes ensue when all arms are killed.
- Head enters Phase 2 at 66% health and Phase 3 at 33% health.
- Head will not spin while any arms are alive and is significantly faster.
- Head gains double defense while spinning and gains speed as it loses health.
- Head begins firing laser circles during its spinning attack at 40% health.
- Head gains a third attack by firing a barrage of 10 homing missiles.
- Head will cycle through these, starting with its circling attack, its spinning charge, and then its missiles.
- All arms gain increased movement and attack speed for each arm killed.
- When all the arms are killed, it gains a new attack by moving in a tight circle and firing homing skull projectiles similar to Skeletron, which alternates with its spin attack.
- Head spawns Probes while performing its skull spin attack.
The changes made to its arms are listed as follows:
Prime Cannon
- Fires rockets instead of bombs. Alternates between firing single rockets and three rockets at once.
- Rockets are shot in a wider spread.
- 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.
In Death Mode
- Fires skulls more frequently and fires more lasers in laser rings while spinning.
- Head gains a speed boost if the player has reversed gravity.
- Head and arms increase in velocity and acceleration as health decreases.
- Has a higher maximum Probe amount.
In Master Mode
- Head and arms have increased speed.
- Spin attack occurs more frequently.
- Arms cycle behavior more frequently.
- Prime Laser and Prime Cannon shoot their respective projectiles at a faster rate.
- Prime Vice charges 2 times instead of 3.
In Revengeance Master Mode
- Has two heads.
- The original head has yellow eyes and controls the Prime Saw and Prime Laser, while the new head has purple eyes and controls the Prime Vice and Prime Cannon.
- The two heads have a shared health bar, defeating one head will automatically defeat the other.
- The second head fires bombs instead of missiles and frost lasers instead of normal lasers.
- Spawns The Destroyer at 75% health, and The Twins at 33% health.
- Destroyer changes:
- Does not become more aggressive based on amount of segments without Probes.
- Cannot fly, use Death Mode laser spreads, and has vanilla movement and enrage distance stats.
- Has 60 segments.
- Despawns at 60% health.
- Probes fire 2 projectiles. This takes priority over Boss Rush and Death Mode's 3 projectiles.
- Twins changes:
- Each eye despawns either at 75% health or at 95% health and the other eye is not present.
- Hovers at a further distance from the player.
- Shoots projectiles and dashes less frequently.
- Projectiles are slightly slower.
- Have decreased speed.
- Destroyer changes:
- Heads can only start attacks when 21 blocks above the player.
- Can immediately use its spin attack and its spin attack occurs more frequently.
- Heads and arms have increased speed.
- Shoots skulls more frequently and with a higher spread and speed.
- Missiles are shot more frequently and 12 are shot instead of 10.
- Arms switch behavior more frequently.
- Prime Laser shoots circles of 24 lasers instead of 16.
In Death Master Mode
- Spin phases begin much quicker.
- Laser spreads have 15 lasers instead of Death Mode's 18.
- Spawns up to 3 Probes instead of Death Mode's 4.
- Skull projectiles are even faster.
- Missiles are shot even more frequently.
During the Boss Rush
- Maximum health increased to 1,100,000 / 1,650,000 / 1,980,000 .
- Sets the time to 7:30pm.
- Moves much faster.
- Prime Cannon fires out 5 rockets instead of 3.
- Head occasionally fires homing martian rockets.
- Head and the Prime Laser fire more lasers and attack much more frequently.
- Head spins for less time as health decreases and at increased velocity.
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.
- If The Twins and The Destroyer have also been defeated:
- The Bandit will begin selling the Momentum Capacitor.
- The Drunk Princess will begin selling Vodka, Screwdriver and White Wine.
- The Archmage will begin selling the Arctic Bear Paw, Frosty Flare, Cryophobia, and Cryogenic Staff.
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 Classic 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 mechanical bosses 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 Rogue players.
- Mollusk armor has very high stats but makes the player 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).
- The Aero Stone, Grand Gelatin, or Frog Leg will improve the usefulness of wings even further and improve vertical motion.
- Terraspark Boots, or its upgrades, 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 the player to drop quickly.
- Using a 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.
- Mage 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 players will find the Raider's Talisman useful to boost their damage output.
Weapons
Melee
- The Caustic Edge is a great pick for melee players due to its easy-to-aim projectile.
- The Storm Saber is also a good choice if you have trouble aiming, because of its two-homing projectiles.
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.
- The Thermocline Blaster 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 its 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.
Trivia
- Skeletron Prime's formal designation, according to Draedon, is HF-04.
- Skeletron Prime's Revengeance Master Mode fight is an homage to Oblivion from the Avalon mod.
- Both fights feature two Skeletron Prime skulls with one having yellow eyes and the other having purple.
- Both fights also summon The Destroyer and The Twins.
History
- 2.0.4.003: Now only swaps targets after each attack is finished, and limbs now target the same player as the head.
- 2.0.4.002:
- Buffed skull projectile and laser damage in Master Mode from 186 to 210 , rocket damage from 222 to 264 , and bomb damage from 240 to 300 .
- Revengeance Master Mode changes:
- Heads can now perform the spin attack, even when limbs are alive.
- The Twins and The Destroyer now leave when below 75% health instead of 70%.
- Decreased The Destroyer's turning speed during the fight.
- The Twins can no longer enter phase 2 during the fight.
- Fixed a game-breaking bug in Revengeance Master Mode that caused players to "merge" and gain control of each other in multiplayer.
- 2.0.4.001:
- Increased the Early Hardmode Progression Rework's health and damage multiplier from 0.8x to 0.9x when fought first, and from 0.9x to 0.95x when fought second in Expert and Master Mode.
- Can now turn the Calamity Boss Health Bar red when enraged, and gray when gaining a temporary defense boost outside of Revengeance Mode.
- Buffed Prime Vice and Prime Saw's damage from 60 / 102 / 136 / 153 / 204 to 70 / 102 / 136 / 170 / 255 .
- Buffed skull and laser damage from 50 / 100 / 124 / 136 / 150 to 50 / 108 / 124 / 140 / 150 , and rocket damage in Death Mode from 160 to 176 .
- No longer uses a global scaling contact damage formula based on boss velocity.
- No longer enrages based on time in the Don't dig up seed.
- Head no longer has reduced acceleration while holding a true melee weapon.
- Prime Laser and Prime Cannon no longer deal contact damage in all difficulties.
- Decreased laser and rocket On Fire! duration from 4 seconds to 3.
- Prime Vice no longer deals contact damage while not swiping in all difficulties.
- Prime Saw now deals half contact damage while not swiping or directly moving towards the player in all difficulties.
- Head now inflicts Bleeding for 5 seconds while spinning, and Prime Saw now inflicts Bleeding for 3 seconds.
- Prime Cannon's bombs now inflict On Fire! for 3 seconds.
- Revengeance Mode changes:
- Prime Cannon's rockets are now shot in a wider spread, but no longer home in.
- Now enters phase 2 at 66% head health instead of 50%, and phase 3 at 33% head health instead of 25%.
- No longer kills all limbs when entering phase 2.
- Skulls now home in for longer and have better turning speed, and can now spawn Probes during the skull spin attack.
- Increased speed and acceleration during the missile attack, and increased missile homing speed and acceleration.
- Now spawns more lasers in laser rings while spinning and has a higher maximum Probe amount in Death Mode.
- Now has a higher acceleration but lower velocity during idle phase, switches between idle and spin faster, has a faster spin velocity, Prime Laser shoots lasers faster, Prime Cannon shoots bombs faster and bombs can blow up on platforms and when close to the player, Prime Saw and Prime Vice charge faster, and all limbs have higher acceleration and velocity in Master Mode.
- Now spawns a second Skeletron Prime head with different attacks that owns Prime Vice and Prime Cannon, moves faster during the skull spin attack, spawns more missiles and spawns them faster, additionally spawns both The Twins and The Destroyer in nerfed states during the fight, Prime Laser switches between single lasers and laser rings faster and has more lasers in laser rings, and Prime Cannon switches between single rockets and rocket bursts faster in Revengeance Master Mode.
- Increased spin velocity in Boss Rush.
- Fixed projectiles not dealing less damage with the
Early Hardmode Progression Rework
config option enabled.
- 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.
- 1.4.5.004:
- 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.
- 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.
- 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.
- Revengeance Mode changes:
- 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.
- Buffed Boss Rush health from 780,000 to 980,000.
- 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.
- 1.3.3.001: Limbs are now affected by the early Hardmode health and damage nerfs.
- 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.
- 1.1.7.801: The status message "A blood red inferno lingers in the night..." now appears when defeated.