The story takes place one year after Costume Quest 2. Reynold and Wren, alongside Everett and Lucy, getting ready for Auburn Pines's annual Halloween block party, when suddenly, they see a businessman walking down the road. they try to go up to him, but then, a hooded stranger grabs them, and takes them to the Repugia gate in Fall Valley. the stranger is revealed to be the wizard and witch duo Dorian and Dorsilla. they are also joined by Kronoculus, the time master from the last game.
Suddenly, out from a nearby time portal, comes the adult versions of Reynold & Wren, who warn them that Auburn Pines is in danger. and they need their past selves' help to save it, as well as Halloween. So they must form a team to save them. Dorsilla, hoping to make up for her error in the first game, volunteers to choose the leader of the team [after a comedic argument from the siblings]. The player must choose who out of the kid versions of Reynold & Wren will lead.
The one the player chooses is made the leader. Dorsilla provides the two with costumes [Gingerbread Person & Candy Corn],
Reynold, Wren, and Ryan make it back to the camp, to find a message.
Reynold and Wren end up captured and locked up in Bill's tower. They meet Tasha, who explains she was recently grounded because of her dislike of her dad's plan. Reynold and Wren allow her to help them. She releases them from the cell, and a
Bill gets mad at the team for wrecking his plans. He decides to propose a wager - if they can beat him, he will give up his plans for Auburn Pines. If they lose, their town will be bulldozed to drill for oil, also planning to kill the kids of the adult Reynold & Wren, as well as the adult Lucy & Everett and their daughter Halley [from the last game], and their kid selves too, in the process. Not wanting to have their friends lost to a bulldozer, the leader accepts the challenge.
However, Bill refuses to win easily, so he drinks a potion he stole from Dorsilla earlier to turn himself into a monster
Officer Nichols shows up and apprehends Bill, placing him under arrest. Tasha is almost arrested, but Reynold & Wren convince the officer to spare her, since she never did anything wrong.
pretty much the same, except that the characters can now jump.
Though it returns in the PS3 & PS4 versions of this game, the Sackboy Costume is not included, for it behaves the same as in Costume Quest 2.
|Costume||What it turns you into in the battlefield||Focus||Normal Attack||Combo Move [once unlocked]||Special Ability||Upgrade||Where you get it||Exploration ability||Strong vs||Weak vs|
|Gingerbread Knight||a gingerbread boy or girl, depending on who wears it, using a candy cane as a sword||Sweet Damage||Candy Cane Sword - The Gingerbread Person swings the candy cane sword like a knight.||The 'Mighty Cleave' technique from Skylanders: Imaginators||Peppermint Fury - Gingy's slam attack from Shrek Super Slam.||Streamers - colourful icing & decorations gives stronger damage to the candy cane sword!||Start of the game.||None||Magic||monster|
|Candy Corn||a Candy Corn. need i say more?||Inaction||None||none||none, but is sweet and draws attention. But it retains the Glisten ability from Costume Quest 2 [Final boss only]||same as in Costume Quest 2||Start of the game||none||same as in Costume Quest 2||same as in Costume Quest 2|
|Cupcake||a fairy princess, like Holly from Ben & Holly's Little Kingdom, but with the colours of the cupcake icing on her dress, and the candle of Candlehead's hat as her wand.||Healing||Wand Swing - The fairy swings it's wand like a hammer.||The fairy does a spin with the wand||Sweet Victory: a burst of sweet happiness heals the team.||Snow Blanket - Top your cupcake with whipped cream to make heals more sweeter.||You get it from a cupcake seller in Repugia.||Lure||Tech||Undead|
|Firefly||a firefly with a bright yellow light, and a green body, head, blue eyes, and red antennae.||Stun||Firefly Fists - The firefly does rapid quick punches.||The firefly headbutts the enemy.||See the Light: the firefly turns his bulb VERY bright, and zaps the enemies, stunning them||Spotlight Bulb - a brighter light stuns enemies for longer!||Light up dark areas||Magic||Monster|
|Chameleon||A giant green chameleon||Defense||Rolling Thunder - The chameleon rolls into a ball and rams an opponent.||The chameleon jumps on the enemy.||Camo Cloak: The player makes himself or someone else invisible, so attacks from the enemy might miss.||Dark Sunglasses - gives you a secret agent chameleon, with better invisiblity that affects everyone!||You find the pieces in the home area of Bill's tower. Tasha gives you the pattern.||Stealth||Monster||Tech|
|Chicken||a giant white chicken.||Weaken Enemies||Mega Peck: The chicken jumps and pecks the opponent hard.||The chicken fires an egg from behind onto the enemy.||Egg-streme Pain: the chicken fires eggs at the chosen enemy, weakening them.||Brown Paint - brown hens give more eggs with stronger weakening power for all enemies!||flap||Monster||Magic|
|Angel||an angel with huge wings and a blue dress||Revival||Flying Halo - the angel throws her halo like a ninja star.||The angel's halo creates a light beam that zaps the enemy.||Halo of Revival: This revives a KO'ed player [heals if there's no knocked out players]||White dress - a pure white dress will give more health in revivals! [but heals the whole team if nobody is knocked out]||zipline||Undead||Tech|
|Merman/Mermaid||A muscular man with a green beard and green hair. Holds a trident in his right hand. Under his torso is a blue mermaid's tail. the girl's form is a mermaid with a bikini made of starfish, with the same hair and tail.||Splash Damage||Trident attack - the merman/mermaid swings his/her trident like a sword.||the merman/mermaid whips with his/her tail.||7 Seas: A big wave of water splashes all enemies with powerful force!||Toy medal - a starfish necklace boosts your splash damage!||none||Tech||Magic|
|Cactus||A two-arm Saguaro cactus with huge eyes and a sombrero, in a pot with 4 green root-like spider legs||Overtime damage||1000 Needles - Cactuar's Mario Sports Mix Special move.||Silicone Flower: a cactus with a flower gives more overtime damage!||none||Monster||Tech|
|Masked Archer||a man wearing the Archer outfit from Sly Cooper: Thieves in Time, with grey pants, a mask and a bow and arrow.||Nuke||Arrow Shot||the archer fires an arc arrow||Volley Storm: A rain of arrows hurts all enemies.||Firey Orange Fabric: Your arrows are now infused with flames!||Generosity||Undead||Monster|
|Octopus||an octopus based on the enemies from Spyro: Year of the Dragon||Multi-attack||Tentacarousel - the octopus spins with all of his tentacles out that attacks everyone||The octopus uses his tentacles like a huge golf club and whacks all enemies at once.||Tentacle Carousel - the octopus spins around, whirling it's tentacles around like a carousel, complete with speedy carousel music playing.||Purple paint - the octopus attacks now deliver poisonous ink to all enemies!||Grapple||monster||tech|
|Vanellope Von Schweetz [DLC]||Vanellope from Wreck-It-Ralph||Glitch Defence||Vanellope Tackle - Same as Sack Attack.||Vanellope throws a Cherry Bomb at the enemy||Glitch: the player uses a glitch that defends a random party member or themselves for 1 turn, reducing the damage taken, and also, anyone who hits you will be damaged, regardless of their weakness.||Hair pins: the glitch now affects the whole team and lasts longer.||Part of the Disney Costume Pack, unlocked by downloading the costume or the pack, appears in the shop||none||tech||magic|
|Snow Queen [DLC]||Elsa from Frozen||Freezing Stun||Freeze Wave||Elsa blasts a wave of ice||Let it Go: Elsa launches a blast of cold ice towards the enemies, freezing them for 1 turn.||Green Dye - give the enemies a bout of Frozen Fever, freezing them for longer!||Part of the Disney Costume Pack, unlocked by downloading the costume or the pack, appears in the shop||none||Magic||undead|
|Fredzilla [DLC]||Fred's super suit from Big Hero 6||Freak Damage||Kaiju Tail Whip||Fredzilla beathes fire.||Kaiju attack: like LittleBigBeatdown.||Black dye - A stealthier Kaiju equals more power!||Part of the Disney Costume Pack, unlocked by downloading the costume or the pack, appears in the shop||none||Monster||Magic|
|Disco Dancer||Boy: An adult man with sunglasses, a beard, a brown afro, and a colorful disco dance suit
Girl: a woman with blonde hair and a colorful dance dress.
|Power Booster||Disco Kick||The Disco Dancer does a rockstar powerslide into the enemy||Power Rhythm: Disco Dancer dances, points his/her finger in the air, and boosts the chosen player's attack power for 2 turns.||Sparkle Glitter - Trade in your old suit for a super sparkly one, that gives your team more attack power!||find the hidden room in Bill's tower, and open the chest||none||Monster||Magic|
|Biznis Bot Drone Disguise||not for battle||espionage||none||none||none||none||find the parts to construct it||espionage||none||none|
|Ratchet & Clank [Playstation versions only]||Ratchet in his Tools of Destruction suit, with Clank on his back.||Galactic Damage||Wrench Combo - the wrench combo from the Ratchet & Clank games||A Hyper Strike, also from the Ratchet & Clank games||RYNO V: Ratchet fires his RYNO V at all enemies, damaging them severely.||Tinfoil - gives Ratchet his Trillium Armor Look. Also provides extra damage, and is more resistant to damage.||exclusive to PS3/PS4; in the shop.||none||tech||magic|
|Mumbo Jumbo [Xbox versions only]||Mumbo Jumbo in his design from Banjo-Kazooie: Nuts & Bolts.||Damage + Stun||Mumbo Wrench Combo - Mumbo swings the wrench in a combo attack||Mumbo does his magic shock attack from Banjo-Tooie.||Jiggy Rain: Mumbo waves the wrench, and jiggies fall down on all the enemies, sometimes stunning them.||Gold spray paint - Mumbo's feathers turn gold, allowing stronger damage, and increased chance of stunning enemies.||exclusive to Xbox 360/Xbox One; in the shop.||none||magic||undead|
|Paulie Pretztail [Xbox versions only]||Paulie Pretztail in his design from Viva Piñata TV Series and Viva Piñata: Party Animals.||Defense||Pinata Jump - Paulie jumps on the enemy 3 times.||Paulie lobs an explosive pinata at the enemy||Stick Hit: Paulie gets out his stick and hits the enemy with it.||Rainbow Paint - turns Paulie into a rainbow version of him, which allows him to do more damage.||exclusive to Xbox 360/Xbox One; in the shop.||none||Magic||Tech|
|Bowser [Wii U only]||Bowser from the Mario games. Nuff said.||Overtime Damage||Bowser Punch - Bowser punches the enemy with force.||Bowser goes into his shell and spins toward the enemy.||Bowser Flame: Bowser breathes a wave of fire on all enemies, letting them burn and doing damage overtime.||Black & White Paints - turns Bowser into Dry Bowser, allowing blue flames that burn and deal damage longer.||exclusive to Wii U/Switch; in the shop||None||undead||magic|
|Sceptile [Wii U only]||Sceptile from Pokémon Ruby/Omega Ruby and Sapphire/Alpha Sapphire.||Overtime Damage + Stun||Leaf Blade: Self-explanitory.||Slams with his tail.||Grass Knot: Sceptile knots grass at his enemies, which damages them for 3 turns, with a chance of being stunned instead for 1 turn.||Mega Power - turns Sceptile into Mega Sceptile, allowing him to damage his enemies for longer time, and increased chance of stunning enemies.||exclusive to Wii U/Switch; in the shop.||None||Monster||Tech|
This DLC pack contains costumes from Costume Quest 1 and 2, and Grubbins on ice, and when you download them, you can unlock these costumes in the shop for only 5 bits of candy!
|Costume||Game it's from||Upgrade|
|Superhero||Costume Quest 2||same as Costume Quest 2|
|Liberty||Costume Quest||White star stickers - provide an anthem full of stars that give super honorable heals, American style!|
|Eyeball||Grubbins on Ice||Same as in Costume Quest 2|
|Robot||Costume Quest||same as in Costume Quest 2, but with green paint instead of red.|
|Pharaoh||Costume Quest 2||same as Costume Quest 2|
List of goods for Party Mode
Certificate 1: Start Your Fighters: Get the jump on 15 enemies by hitting them.
Certificate 2: Costume Plus: Get all Costumes & their upgrades
Accessory: Bill-zilla Costume: Defeat Bill-zilla & save Auburn Pines from destruction