NOXUS: People in costume show up at your house once it’s dark. They demand candy and if you don’t have any, they’ll take money to buy candy. Most households keep some candy on hand to placate these strange, masked hooligans who will deface their house otherwise.
DEMACIA: Practically everyone dresses up as a noble or a member of the military. What other heroes are there? Children are chaperoned. Adults who trick-or-treat take their own candy with them, then exchange it at houses - or if it’s a house with no candy, they give up their own to ensure the children will have some.
PILTOVER: The Sheriff sends organizes extra patrols to keep the children safe while they trick-or-treat. Adults enjoy dressing up as well and ‘chaperoning’ the children though really it’s just an excuse to show off their own costumes. The Defender of Tomorrow and the Piltover Enforcer are especially popular costumes with the children, though adults know better than to dress in anything that might attract Jinx’s attention.
ZAUN: The smog means everyone wears masks when they trick-or-treat. The chaotic, dangerous nature of the city makes people nervous to go door-to-door in case they get kidnapped and used as a lab animal but some people set up stalls giving out candy. It may or may not be drugged. Accept at your own risk.
IONIA: Peaceful festival to honor the dead. Quiet, low-key. People dress up as their guardian spirits, their ancestors, their hopes for the future - whatever they like. Mostly a festival of remembrance for those who have passed, a time to visit and tidy grave sites. Everyone carries and exchanges homemade candy, giving it as a gift on behalf of the dead. The names of the dead being remembered are often written on the wrappers which are burnt the next morning.
BILGEWATER: Mostly, people are busy fighting off the Shadow Isles. Some parents dress their children like Shadow Isles monsters to protect them while other adults don costumes of their own in the hopes that the Shadow Isles denizens won’t recognize them during the rest of the year.
SHADOW ISLES: The Black Mist isn’t actually a horrible attempt from the Shadow Isles to take souls. They’re just trick or treating but instead of candy, they want souls. Afterwards, they return home and compare their loot, often trading souls back and forth until everyone’s satisfied. The only exception is Kalista who crosses over when the others have returned and makes pacts with those who’ve lost loved ones to the Black Mist.
FRELJORD: If you’re willing to venture out in the cold, you deserve all the candy you can carry. It’s too cold to go door-to-door so instead, they have costume parties where kids and grown ups alike can dance and be merry. Bowls of candy, mostly syrup frozen on snow, are on the tables for people to help themselves.
SHURIMA: Once it’s dark and relatively cool,everyone comes out in their costumes to gather near the fountains and in the marketplace. Merchants set up with bowls of candy and pastries, considering this a good time to hand out samples of their wares and build up good will. Even merchants who don’t sell sweets will have some to give out. It’d be a sign of poverty otherwise and make people think their business is going badly. Plenty of music, plenty of laughter and plenty of candy with some of the bolder parties even going to the palace to ask for sweets.
BANDLE CITY: The yordles consider trick or treating to be a human custom but yordle children like the idea of free candy enough that it happens anyway. Little yordles dressed in their costumes look adorable and often end up with sacks of candy as big as they are. Just don’t take any cupcakes from Lulu. Seriously.
VOID: …Don’t trick or treat in the Void. The Void monsters will think it’s a trick and that you’re the treat.