Many folk beliefs generally paint fairy rings as dangerous places, best avoided. Sikes traces these stories of people trespassing into forbidden territory and being punished for it to the tale of Psyche and Eros. In it, Psyche is forbidden to view her lover, and when she does so, her palace disappears and she is left alone. Superstition calls fairy circles sacred and warns against violating them lest the interloper (such as a farmer with a plough) anger the fairies and be cursed. In an Irish legend recorded by Wilde, a farmer builds a barn on a fairy ring despite the protests of his neighbours. He is struck senseless one night, and a local "fairy doctor" breaks the curse. The farmer says that he dreamed that he must destroy the barn.[60] Even collecting dew from the grass or flowers of a fairy ring can bring bad luck. Destroying a fairy ring is unlucky and fruitless; superstition says it will just grow back.
A traditional Scottish rhyme sums up the danger of such places:
Numerous legends focus on mortals entering a fairy ring—and the consequences. One superstition is that anyone who steps into an empty fairy ring will die at a young age. A 20th-century tradition from Somerset calls the fairy ring a "galley-trap" and says that a murderer or thief who walks in the ring will be hanged. Most often, someone who violates a fairy perimeter becomes invisible to mortals outside and may find it impossible to leave the circle. Often, the fairies force the mortal to dance to the point of exhaustion, death, or madness. In Welsh tales, fairies actively try to lure mortals into their circles to dance with them. A tale from the Cambrian Mountains of Wales, current in the 19th century, describes a mortal's encounter with a fairy ring:
Entering the ring on May Eve or Halloween night was especially dangerous. One source near Afon fach Blaen y Cae, a tributary of the Dwyfach, tells of a shepherd accidentally disturbing a ring of rushes where fairies are preparing to dance; they capture him and hold him captive, and he even marries one of them. In variants from Scotland recorded by Edwin Sidney Hartland in 1891, the ring is replaced by a cavern or an old mill.
Freedom from a fairy ring often requires outside intervention. A tactic from early 20th-century Wales is to cast wild marjoram and thyme into the circle and befuddle the fairies; another asks the rescuer to touch the victim with iron. Other stories require that the enchanted victim simply be plucked out by someone on the outside, although even this can be difficult: A farmer in a tale from the Llangollen region has to tie a rope around himself and enlist four men to pull him from the circle as he goes in to save his daughter.[71] Other folk methods rely on Christian faith to break the enchantment: a stick from a rowan tree (thought to be the wood from which the cross of Jesus Christ was built) can break the curse, as can a simple phrase such as "what, in Heaven's name", as in a 19th-century tale from Carmarthenshire. A common element to these recoveries is that the rescuer must wait a year and a day from when the victim entered the ring.
Mortals who have danced with the fairies are rarely safe after being saved from their enthrallment. Often, they find that what seemed to be but a brief foray into fairyland was indeed much longer in the mortal realm, possibly weeks or years. The person rescued from the fairy ring may have no memory of their encounter with the sprites, as in a story from Anglesea recorded in 1891. In most tales, the saved interlopers face a grim fate. For example, in a legend from Carmarthenshire, recorded by Sikes, a man is rescued from a fairy ring only to crumble to dust. In a tale from Mathavarn, Llanwrin Parish, a fairy-ring survivor moulders away when he eats his first bite of food. Another vulnerability seems to be iron; in a tale from the Aberystwyth region, a touch from the metal causes a rescued woman to disappear.
Some legends assert that the only safe way to investigate a fairy ring is to run around it nine times. This affords the ability to hear the fairies dancing and frolicking underground. According to a 20th-century tradition of Northumberland, this must be done under a full moon, and the runner must travel in the direction of the sun; to go widdershins allows the fairies to place the runner under their sway. To circle the ring a tenth time is foolhardy and dangerous. Keightley recorded a similar tradition from Northumberland in 1905: "The children constantly run this number [nine times], but nothing will induce them to venture a tenth run." A story from early 20th century England says that a mortal can see the sprites without fear if a friend places a foot on that of the person stepping beyond the circle's perimeter.[76] Another superstition says that wearing a hat backwards can confuse the fairies and prevent them from pulling the wearer into their ring.
Although they have strong associations with doom, some legends paint fairy circles as places of fertility and fortune. Welsh folk belief is that mountain sheep that eat the grass of a fairy ring flourish, and that crops sown from such a place will prove more bountiful than those from normal land. A folk belief recorded in the Athenian Oracle claims that a house built on a fairy circle will bring prosperity to its inhabitants.[78] Likewise, a legend from Pont y Wern says that in the 13th or 14th century, the inhabitants of the town of Corwrion watched fairies dancing in a ring around a glow worm every Sunday after church at a place called Pen y Bonc. They even joined the sprites in their revels. The legend survives in a rhyme: "With the fairies nimbly dancing round / The glow-worm on the Rising Ground." A Welsh tale recorded by Rhys in 1901 tells of a man who supposedly lived on the side of the Berwyn, above Cwm Pennant, in the early 19th century. The man destroyed a nest of rooks in a tree surrounded by a fairy ring. In gratitude, the fairies gave him a half crown every day but stopped when he told his friends, "for he had broken the rule of the fair folks by making their liberality known".[80] Nevertheless, fairy boons are not without their curses, and tales often tell of the sprites exacting their revenge.