Finn's swords

Finn's swords refer to the types of bladed weaponry that Finn has used throughout his adventures in the Land of Ooo.

Main swords
These are the swords that Finn had mainly used throughout the series.

Finn's golden sword of battle/Scarlet
The golden sword (also known as Scarlet) is Finn's weapon of choice throughout most of seasons one and two. The blade is dented, chipped, and dirty. Its hilt is black with some worn leather grip-straps and a red gemstone in the pommel. In "Business Time," the Businessmen polish and sharpen the sword, making this episode the only one in which the golden sword appears to be in excellent condition.

In "The Real You," the golden sword passes through the Bubble creator and becomes four-dimensional. When Finn uses the 4-D golden sword to attack the black hole he created, Finn's golden sword is sent into the Cotton Candy Forest by the explosion. Finn is without a sword until "Mystery Train", which could mean he lost it after the explosion.

In the video game "Adventure Time: Hey Ice King! Why’d you steal our garbage?!!," this sword has a name, Scarlet and Jake refers to it as "she."

Root sword
In "Mystery Train," Finn obtains the root sword (the name is non-canonical), which becomes his primary weapon. He finds the sword on the caboose of the train and uses it to attack The conductor. He next uses it against the Giant in the beginning of "Belly of the Beast." It is seen briefly in "Mortal Recoil," when Finn throws it at Ice King, "Conquest of Cuteness," and in "Jake vs. Me-Mow." He keeps it in a makeshift pocket on the side of his backpack. It can be seen again in the Issue 1 (although the comics are non-canonical).

The sword gets its name from its root like handle, that seems to be comprised of 2 main "roots" spiraled around one another. The actual blade is a slightly pinkish tone of silver, double sided, and in good condition with the exception of a small chip on one of the blade's sides.

Demon sword
The Demon sword first appears in the episode "Dad's Dungeon." In the episode, Finn and Jake go to Joshua's Dungeon to retrieve Jake's family sword. At the end of the dungeon Finn finds it encased in locks and stone. He breaks it loose and uses it to fight the final monster of the dungeon. The sword is made out of Demon Blood, which causes Blood Demon to sporadically appear and plead to Joshua (and later, Jake, thinking he's Joshua) for the return of his blood. Blood Demon is easily banished away using the spell "Kee Oth Rama Pancake." In "Return to the Nightosphere," Finn spins it in front of the blood mist cloud, and hits Marceline with it, thinking she is Hunson Abadeer. The sword also shows immunity to Marceline's blood mist cloud blasts. In "Daddy's Little Monster," Finn can be seen holding it throughout the video files on Jake's video phone. In "Beyond this Earthly Realm," Finn uses it to slash one of the heads from The Dead One. In "Gotcha!" he uses it to save Lumpy Space Princess from the Mirror Finns. It also appeared in "All the Little People" and "Puhoy". In "Vault of Bones" it is shown to be immune to fire.

Minor swords
These are the swords Finn has kept at the Tree Fort.

Steel sword
In the episode "Morituri Te Salutamus," Finn picks up a steel sword during his first battle in the Fight King's Arena; it is similar to his original gold sword. The hilt has a leather grip and the pommel has a purple gemstone with a tiny pink gemstone slit in the center. The sword itself is in very good condition. It is later seen again in the episode "Still."

Pink jewel sword
In "Slow Love" there is a pink jewel sword, with a hilt that is pointed on both sides and a pink gem on the bottom. The sword is seen slicing Finn's bed in half, but Finn has not been seen using it himself.

Katanas
Finn has two golden katanas in the episode "Slow Love." They are used by Finn when he teaches Snorlock to do sword tricks.

Loot Swords
Various swords, daggers and other weapons can be found scattered throughout Finn and Jake's Tree Fort; though, they are never used by Finn.

Frozen sword
In "Fionna and Cake" Finn is frozen in an ice cube and holding a sword that appears similar to his golden sword but without the red gem in the pommel.

CG Sword
In the episode "A Glitch is a Glitch" Finn uses a sword like his golden sword but with the coloration of the sword in the logo.

Temporary swords
These are the swords Finn had temporarily used or imagined.

Sword of the dead
Finn wields the sword of the dead to defeat Marceline's father in "It Came from the Nightosphere." Finn draws the sword from the Grass Lands before his battle and slits open the pods in Hunson Abadeer's gullet, which he is using to imprison the souls of Ooo. Finn drops the sword while reciting the incantation to open a portal to the Nightosphere.

Dual swords
While Finn is under the "control" of Fight King in the episode "Morituri Te Salutamus," he fights with dual swords that look like a single sword that was completely split apart from the tip of the blade to the pommel. When Finn is forced to fight Jake, he only uses one of them.

Crystal sword
In "Mortal Folly" when Finn, Princess Bubblegum, and Jake meditate, Finn is grown up in his imagination. The imaginary Finn has a new crystal sword in a back scabbard.

Dungeon sword
In "Dungeon," Finn uses a sword he found in the dungeon to fight off Eye Creatures, but the fiery creatures melt it shortly before Princess Bubblegum rescues Finn and Jake.

City of Thieves sai
Finn steals two sai in the episode, "City of Thieves" but they are taken by two angels at the end.

Dagger of chilled glass
When Finn and Jake learn ninja skills in "The Chamber of Frozen Blades" Finn creates the dagger of chilled glass using his ninja skills.

Dagger
Finn picks up a twisted, yellow dagger outside the windmill when he and Jake approach the "monster" in the episode "The Monster." It resembles a kris, an Indonesian dagger considered to possess magical powers. A fat villager was later seen wielding a similar dagger.

Shark sword
In "King Worm," Finn imagined a sword that he planned to use to blast a hole in the wall. However, Finn never got to use it because he thought about a shark trying to bite off his face and unintentionally changed the sword's blade into one.

Rusty Sword
A rusty sword (also called "Finn's Sword") can be acquired in the game Righteous Quest 2. It can be unlocked by completing the Lumpy Space level. It is used to clear thorns to enter hidden areas.

Arm sword
Farmworld Finn uses a blade that locks into his mechanical arm after taking the hand off in "Finn the Human." He receives it from Choose Bruce and uses it to fight the Destiny Gang. It is later discarded.

Trivia

 * The sword in the Adventure Time logo has never been used, other than in the promo video. However, a version of it was imagined by Finn while dreaming in "King Worm."
 * The yellow twisted dagger Finn used looks similar to Me-Mow's dagger.
 * In the collector's edition of the game Adventure Time: Hey Ice King! Why’d you steal our garbage?!! there is a stylus resembling Finn's golden sword.
 * This design of the golden sword is the basis for the 24-inch toy version of Finn's sword, which is labeled as "Finn's Golden Sword of BATTLE."
 * Finn doesn't used any swords on the Animated short. However, a sword can be seen on the logo of the animation.