Calamity Mod Wiki
  • Murasama.gif
Stack digit 1.png
Damage20001 Melee
Knockback6.5 (Strong)
Critical chance34%
Use time25 Fast
TooltipThere will be blood!
ID and power-level locked
Prove your strength or have the correct user ID to wield this sword
RarityRarity Level: 15
Sell 50 Gold Coin.png
Projectile created
Murasama Slash
Murasama Slash

"It was tempered by the fires which are fueled by spirits, and formed in the magma I draw into my laboratories."

Not to be confused with Muramasa, a vanilla broadsword.

The Murasama is a post-Moon Lord melee weapon resembling a sword. It can be found in The Underworld's Bio-center Arsenal Lab, contained within a Security Chest. Although Murasama is technically attainable in Pre-Hardmode, it cannot be swung until Jungle Dragon, Yharon has been defeated in the current world. It possesses a larger than normal critical strike chance.

While being swung, large red electric slashes will be swung in the direction of the cursor, and any enemies that are hit by the slashes will take damage. The slashes appear in a set looping order: one large upward slash, one larger electrified upward slash, and then a slightly smaller downward slash. Each slash deals the same amount of damage. The Murasama emits bright red particles outward as it swings.

Its best modifier is Godly. It cannot get modifiers that affect size. Ruthless might be preferred if the player already has 100% critical strike chance.


  • The Murasama cannot attack through walls.
  • The sword can be used at any point before defeating Yharon if the character's name is "Jetstream Sam" or "Samuel Rodrigues".


  • Using the melee version of the Silva armor or the Auric Tesla armor will greatly increase the damage output of this weapon, as they both grant a 25% chance for true melee hits to deal 5x damage.
    • This makes the Murasama very useful for the Boss Rush, as it can cut through most of the bosses within seconds.


  • The Murasama has a Draedon's Log entry dedicated to it, also found in the Underworld Bio-center Lab, where it is depicted alongside the Phaseslayer.
  • The Murasama is one of several references to Metal Gear Rising: Revengeance, the others being the Boss Health Bar, Red Sun, Excelsus and Revengeance Mode alongside other minor references. The Murasama is wielded by one of the game's main antagonists, Jetstream Sam.
    • The fast, blurred cutting animation that the item uses is based on the blurring visuals shown when the player or Sam uses the sword.
      • The fact the weapon is "ID locked" is also a reference to Sam, for the inability of using his weapon immediately after defeating him, unlike the other bosses in Metal Gear Rising.
    • The weapon's tooltip, "There will be blood!", is a reference to the lyrics of "The Only Thing I Know For Real", which is Sam's boss theme.
  • Prior to being located in Underworld Arsenal Labs, the Murasama was generated in now-removed Underworld Shrines. Before that, the Murasama was a Revengeance-exclusive weapon dropped by The Devourer of Gods. And before that, it was dropped by The Devourer of Gods in the now-removed Prepare to Cry mode.
  • The Murasama has the highest base damage out of all the mod's melee weapons.