Before a decisive battle, the character tosses away his weapon's sheath (usually that of a sword) to demonstrate that he will not back down from the fight. A darker implication of this gesture is that the character realizes that his chances to survive are slim and he won't have a chance to sheathe his weapon ever again.
Aside from the symbolic meaning, putting away your sheath has a purely practical rationale: The sheath usually gets in the way during a fight, and the enemy can grab it to restrict your movement. Contrast Sheath Strike, however.
As mentioned, this works best with bladed weapons, since more modern ones, like firearms, lack an exact analog to a sheath. Throwing away a holster just doesn't look as dramatic.
- Kojiro's incident mentioned below in Real Life is parodied in Yaiba: due to a time-traveling hijink, Yaiba has to pass as Musashi and duel against Kojiro at Ganryuujima while the real deal is still sleeping in a drunken stupor. He expects Kojiro to do this, but is flabbergasted when Kojiro just plants the sheathe beside him, and actually forces him to pick up the scabbard and throw it in the sea to reenact the famous statement. Kojiro isn't amused.
- Again, parodied in the Jiro vs Musaku's duel in Yatterman: when Jiro throws away his scabbard and Musashi tells him that he's not planning to win, Jiro pulls the scabbard back to his hand with a rope as an answer.
- On Gor, a Warrior carries his sword in a baldrick. While on the march it's slung over the right shoulder (assuming the Warrior is right handed) with the sword on the left hip, to give some security; but when preparing for battle it's slung over the left shoulder so it can be quickly discarded.
- Not a literal example, but in The Lord of the Rings: Return of the King (both the book and the movie), Aragorn unsheathes Anduril on the last ride to Mordor and vows that it shall not be sheathed again until the fight is over.
- Before his duel with Phrygiar Navaris in Captain's Fury in the Codex Alera, both Tavi and his opponent are noted as having their seconds hold onto the sheaths of their weapons because they would just get in the way.
- During the climactic chapter of Lioness Rampant, Alanna the Lioness discards her sheath while descending into the palace.
- In Kara no Kyoukai chapter 5 (particularly, the movie), Shiki very deliberately tosses away her katana's sheath when when confronting the Big Bad for the second and final time. It turns out to be doubly appropriate, since the katana no longer needs a sheath after their fight is over, seeing how it's broken in half in the end.
- From the Scottish folk song "Gallant Murray":
"His good sword he now has drawn it,
And he's flung the sheath away"
- In Asura's Wrath, Augus throws away his sheath when he draws Wailing Dark midway though his fight with Asura.
- In the Dragon Age: Origins trailer "Warden's Calling", the nameless Grey Warden throws away his sheath before charging at a horde of Darkspawn.
- It isn't focused on, but it is noticeable that Vergil disregards his sheath while running at Mundus at the end of the third Devil May Cry. Despite his brave words, it's easy to interpret it that he is well aware of how insane this challenge is and how unlikely he is to make it out alive.
- In Final Fantasy X, Yojimbo's awesome-as-hell Zanbato move has him slowly draw his sword, dramatically throwing away the sheath.
- In Tales of Vesperia, Yuri Lowell typically does this at the start of every battle, flinging the sheath across the screen one-handed as he readies his blade.
- Yu Narukami tosses his katana's sheath away in one of his intro animations for Persona 4: Arena.
- As they invade Dracula's castle in Castlevania (2017), Alucard does this in his usual over-the-top manner. He levitates his sword horizontally in front of him, then dramatically reaches out, takes the sheath off it and tosses it away, before the sword moves to float over his shoulder. In all, far more effort than it would've been to just draw it normally, but it looks cooler.
- John Singleton Copley invoked this trope when talking about The American Revolution: "When the sword of rebellion is drawn, the sheath should be thrown away."
- At the start of his (fatal) duel with Miyamoto Musashi, in a rage over Musashi's late arrival, Sasaki Kojirō supposedly drew his katana and threw the sheath away, possibly into the ocean. Musashi turned this around by observing that Kojirō must not be planning to win, because otherwise he would need the sheath when the fight was over.