There is a small but fierce cultural divide every 31 October, and it runs roughly along the border. In England, children knock and say "trick or treat". In Scotland, traditionally, children guise — and guising has terms.
You have to do a turn
A guiser arrives in disguise, and is asked what they can do. The correct answer is a performance: a song, a poem, a joke, a party piece. Only then comes the reward — historically fruit, nuts or coins, latterly sweets.
The exchange is the whole point. You are not being given something for turning up. You are being paid for a service rendered at the door, which puts guising in a direct line with souling, with mumming, and with every other British tradition where the poor or the young are licensed once a year to knock and ask.
Scottish and Irish children have done this for centuries, and older Scots are frequently and vocally unimpressed by the modern import. Being handed a fistful of sweets for saying four words strikes them, not unreasonably, as freeloading.
The disguise is the older half
Guise simply means appearance or costume — the same root as disguise. The costume was not originally a matter of fun. If Samhain meant the dead were abroad, going out with your face concealed was straightforward common sense: you passed as one of them, or at least you were not recognised.
Traditional guising costumes had nothing to do with licensed characters. Old clothes, a coat turned inside out, a sheet, soot or burnt cork on the face, and a turnip lantern to light the way. That is the authentic look, and it is markedly more unsettling than a shop-bought vampire cape.
Burns wrote it down
Robert Burns published Hallowe'en in 1785, a long poem cataloguing the Ayrshire Halloween customs of his day — the divination games, the nut-roasting, the whole apparatus of young people trying to find out who they would marry. It is the single best record of what a Scottish Halloween looked like before the Victorians tidied it up, and it makes clear how central the fortune-telling was.
Guising today
It persists, though it is under pressure from the American version. In many parts of Scotland children still expect to be asked for a turn, and many households still ask. Sizeable civic Halloween events run in Edinburgh, Glasgow and beyond, and the Isle of Man keeps its own related custom in Hop-tu-Naa.
If you are handing out sweets in Scotland this year, ask for the joke. The children are ready for it, the tradition survives another season, and the jokes are usually terrible in exactly the right way.