Skeletron Prime Terraria boss · Hardmode · #12 in the usual order

Skeletron Prime in Terraria — Skeletron Prime

A mechanical version of Skeletron with four weapon limbs: a cannon, a saw, a vice and a laser. Only the head needs to die. It is one of the three mechanical bosses and drops Souls of Fright.

Stage: Hardmode
Required?: Needed to progress
Summon: Mechanical Skull
Where: Night, on the surface
Max life: 28,000 (Classic)
Defense: 24

Biome: Space

Stats by difficulty

Stat	Classic	Expert	Master
Max life	28,000	42,000	53,550
Contact damage	47	79	119

Parts
Part	Classic	Expert	Master
Prime Cannon	7,000	10,500	13,387
Prime Saw	9,000	13,500	17,212
Prime Vice	9,000	13,500	17,212
Prime Laser	6,000	9,000	11,475

How to summon Skeletron Prime

Mechanical Skull. Use a Mechanical Skull at night. Craft it from 30 Bones, 5 Iron or Lead Bars, 3 Souls of Light and 3 Souls of Night at a Mythril or Orichalcum Anvil. Once an altar has been broken, there is also a 1 in 10 chance each night that one of the unbeaten mechanical bosses appears on its own.

Attacks and phases

The head hovers above you while its four arms attack: bombs from the cannon, laser shots, and swinging saw and vice.
Every few seconds the head grows spikes and spins after you, dealing much more damage.
If it is still alive at dawn, it charges with deadly speed and damage.

Strategy

Fight on a long sky bridge and keep moving away while the head spins.
Destroying the arms makes the fight easier but takes time; many players focus the head.
In Expert the spin phase is much more dangerous, so take the Prime Saw and Vice out first if you struggle.
Bring Ironskin, Endurance and Regeneration potions.
Summon it right at nightfall so it does not reach dawn.

Recommended weapons

Melee

Adamantite or Titanium Sword, or the Amarok yoyo

Ranged

Clockwork Assault Rifle, or the Megashark if the Destroyer is down

Magic

Crystal Storm, or the Rainbow Rod if the Twins are down

Summoner

Spider Staff with the Cool Whip

Armor and gear for each stage.

Drops

Item	Qty	Chance
Soul of Fright	25–40	100%
Hallowed Bar	15–30	100%
Greater Healing Potion	5–15	100%
Skeletron Prime Mask	1	14.29%
Skeletron Prime Trophy	1	10%

Expert and Master Mode extras

Mechanical Battery Piece Expert · 100%

Robotic Skull Master · 25%

Skeletron Prime Relic Master · 100%

Classic Mode rates. In Expert and Master Mode most loot comes in a treasure bag , which also holds the Expert-only Mechanical Battery Piece.

After you beat Skeletron Prime

Souls of Fright and Hallowed Bars for Hallowed armor, the Flamethrower and the Pickaxe Axe/Drax
The Steampunker can move in after your first mechanical boss
With all three mechanical bosses beaten, Plantera's Bulb grows in the Jungle

Did you know? It is the only mechanical boss with four separate weapon limbs.

FAQ

How do you summon Skeletron Prime in Terraria?

Use a Mechanical Skull at night. Craft it from 30 Bones, 5 Iron or Lead Bars, 3 Souls of Light and 3 Souls of Night at a Mythril or Orichalcum Anvil. Once an altar has been broken, there is also a 1 in 10 chance each night that one of the unbeaten mechanical bosses appears on its own.

How much health does Skeletron Prime have?

28,000 in Classic, 42,000 in Expert and 53,550 in Master Mode.

What does Skeletron Prime drop?

Soul of Fright, Hallowed Bar, Greater Healing Potion, Skeletron Prime Mask, Skeletron Prime Trophy, plus the Mechanical Battery Piece from the Expert Mode treasure bag.

What should I use against Skeletron Prime?

Melee: Adamantite or Titanium Sword, or the Amarok yoyo. Ranged: Clockwork Assault Rifle, or the Megashark if the Destroyer is down. Magic: Crystal Storm, or the Rainbow Rod if the Twins are down. Summoner: Spider Staff with the Cool Whip.

Sources & picture credits

Guide text is original retrogameindex writing, checked against the Terraria Wiki. Boss statistics and drop rates are the game values shown in the Terraria Wiki’s infoboxes. Sprites and artwork © Re-Logic; local copies archived from Terraria Wiki file pages (listed on the image gallery).