Real Knife

For its Neutral and True Pacifist Route counterpart and the item found at the beginning of the game, see Worn Dagger or Toy Knife.

The Real Knife (JP: ほんもののナイフ) is a weapon found in a gift box in Asgore's Home. Plot-wise, it is the Worn Dagger as seen through the lens of a Genocide Route. Its defensive counterpart is The Locket. It is the Genocide Route weapon item associated with the fallen human, and is implied to belong to them.

Attacking

When attacking a monster with the Real Knife, a single bar slides across the attack meter from either the left or the right. When confirming the attack, the animation depicts a curled, red slash animation. This animation and sound effect is shared with the Stick, Toy Knife, and Worn Dagger.

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  The Real Knife's attacking animation

Location

Loading scripts

Trivia

• In the Genocide Route, its existence is foreshadowed in Toriel's Home with the first use of red narration text.
  • The Check and Use flavor texts for the Real Knife reaffirm this.
• Name-wise, it contrasts with the Toy Knife found in the Ruins.
• Like The Locket, Real Knife has little use, as it is only obtained prior to fighting Sans, whose constant dodging and 1 HP both render it useless.
• If the Real Knife is hacked into the protagonist's equipment on a non-Genocide Route, most monsters can be spared on the first turn, even if they cannot be spared normally. This is due to most monsters automatically becoming spareable when the protagonist's next attack could easily kill them.
• Prior to the full release of Undertale, Toby Fox had denied the existence of the Real Knife.
• The Real Knife could possibly be a reference to Mother 3's Real Bat, since both weapons are found before the final battle and wielded by someone before the protagonist, and raise the attack stat to near 100.