Luck stands in opposition to control, but not to causation. Luck is that which happens beyond a persons control. This view incorporates phenomena that are chance happenings, a person's place of birth for example, but where there is no uncertainty involved, or where the uncertainty is irrelevant. Within this framework one can differentiate between three different types of luck:

1. Constitutional luck, that is, luck with factors that cannot be changed. Place of birth and genetic constitution are typical examples.
2. Circumstantial luck, that is, luck with factors that are randomly brought on. Accidents and epidemics are typical examples.
3. Ignorance luck, that is, luck with factors you do not know about.

A rationalist approach to luck includes the application of the rules of probability, and an avoidance of unscientific beliefs. The rationalist feels the belief in luck is a result of poor reasoning or wishful thinking. To a rationalist, a believer in luck commits the post hoc logical fallacy:

A happens (luck-attracting event or action) and then B happens;
Therefore, A caused B.

In this worldview, probability is only affected by confirmed causal connections. A brick falling on a person walking below, therefore, is not a function of that person's luck, but is instead the result of a collection of understood, (or explainable) occurrences. Statistically, every person walking under the building was just as likely to have the brick fall on them.

The gambler's fallacy and inverse gambler's fallacy both explain some reasoning problems in common beliefs in luck. They involve denying the unpredictability of random events: "I haven't rolled a six all week, so I'll definitely roll one tonight".

Luck is merely an expression noting an extended period of noted outcomes, completely consistent with random walk probability theory. Wishing one "good luck" will not cause such an extended period, but it expresses positive feelings toward the one - not necessarily wholly undesirable.

There is also a series of spiritual, or supernatural beliefs regarding fortune. These beliefs vary widely from one to another, but most agree that luck can be influenced through spiritual means by performing certain rituals or by avoiding certain circumstances.

One such activity is Prayer, a religious practice in which this belief is particularly strong. Many cultures and religions worldwide place a strong emphasis on a person's ability to influence their fortune by ritualistic means, sometimes involving sacrifice, omens or spells. Others associate luck with a strong sense of superstition, that is, a belief that certain taboo or blessed actions will influence how fortune favors them for the future.

Luck can also be a [belief]] in an organization of fortunate and unfortunate events. Luck is a form of superstition which is interpreted differently by different individuals. Carl Jung described syncronicity: the "temporally coincident occurrences of acausal events". He described coincidences as an effect of a collective unconscious.

Judeo-Christian and Islamic religions believe in the will of a supreme being rather than luck as the primary influence in future events. The degrees of this Divine Providence vary greatly from one to another; however, most acknowledge providence as at least a partial, if not complete influence on luck. These religions, in their early development, accommodated many traditional practices. Each, at different times accepted omens and practice forms of ritual sacrifice in order to divine the will of their supreme being or to influence divine favoritism.

Mesoamerican religions, such as the Aztecs, Mayans and Inca, had particularly strong beliefs regarding the relationship between rituals and luck. In these cultures, human sacrifice (both of willing volunteers and captured enemies) was seen as a way to please the gods and earn favor for the city offering the sacrifice. The Mayans, also believed in blood offerings, where men or women wanting to earn favor with the gods, to bring about good luck, would cut themselves and bleed on the gods altar.

Many traditional African practices, such as voodoo and hoodoo, have a strong belief in superstition. Some of these religions include a belief that third parties can influence an individual's luck. Shamans and witches are both respected yet feared based on their ability to cause good or bad fortune for those in villages near them.

Some encourage the belief in luck as a false idea, but which may spawn positive thinking, and alter ones responses for the better. Others like Jean Paul Sartre and Sigmund Freud, feel a belief in luck has more to do with a locus of control for events in one's life, and the subsequent escape from personal responsibility. According to this theory, one who ascribes their travails to "bad luck" will be found upon close examination to be living risky lifestyles. On the other hand, people who consider themselves "lucky" in having good health may be actually reaping the benefits of a cheerful outlook and satisfying social relationships, both of which are well known statistically to be protective against many stress-related diseases. If "good" and "bad" events occur at random to everyone, believers in good luck will experience a net gain in their fortunes, and vice versa for believers in bad luck. This is clearly likely to be self-reinforcing. Thus, although untrue, a belief in good luck may actually be an adaptive meme.

Most cultures consider some numbers to be lucky or unlucky. This is found to be particularly strong in Asian cultures, where the obtaining of "lucky" telephone numbers, automobile license plate numbers, and household addresses are actively sought, sometimes at great monetary expense.

• "When it rains, it pours" — this is an expression of the mathematical property of statistically independent events that bunch together.
• "Bad things happen in threes" — see above
• When something happens by "sheer dumb luck", it is considered to have happened unintentionally and without planning.
• A famous Samuel Goldwyn quote sums up the rationalist view: "The harder I work, the luckier I get". Or an equally famous Gary Player quote "The harder I practice, the luckier I get". Other quotes include "Luck is the residue of design" (John Milton) and "Luck is probability taken personally" (Penn Jillette).
• Knocking on wood, spoken expression used as a charm to bring good luck. In medieval times, it was believed that there were spirits living in the trees. One would "knock on wood" for the spirits to gain protection from bad luck.
• "getting lucky" — euphemism for having sex
• "Who dares, wins" — motto of the Special Air Service

• The bearing Isaiah 65:11 has on beliefs concerning luck is a matter of controversy.

Several items or happenings are considered lucky or unlucky.

• Finding a penny with heads facing up
• Horseshoes
• Four-leaf clovers
• A rabbit's foot (unlucky to say 'rabbit' on the Isle of Portland)
• Ladybugs
• Elephant with the trunk pointing up
• The number Seven
• The number Eight (in China)
• Knocking on wood
• Crossing one's fingers
• A tea stalk standing upward on the bottom of a cup
• Having a red piece of string on one's wrist.
• A bird defecating on ones head

• Friday the 13th
• The number 13 (Many buildings skipped 13 when numbering their floors for this reason)
• The number 4 (in China, the word's pronunciation in Mandarin is similar to "si", which means death.)
• A black cat crossing one's path
• Stepping on a crack (the mother's back will break; rhymed as "step on a crack, break your mother's back")
• Stepping on a line in pavement or floor cover (similar to above, rhymed as "step on a line, you'll break your spine")
• Breaking a mirror (seven years bad luck)
• Spilling over salt (When salt was more precious than gold, if one spilt some it was believed to mean that a demon was trying to steal one's salt, but by appeasing it with a little salt over the left shoulder, the demon would leave)
• Putting a hat on a bed
• Opening an umbrella indoors
• Killing a ladybug/ladybird
• Killing a spider in one's home
• Walking underneath a ladder (when being hanged, the condemned man would often be made to pass underneath a ladder before climbing it and onto the gallows)
• Saying "good luck"
• Replying "thank you" to someone wishing good luck
• Picking up a penny face-down (can be avoided by giving the penny away)
• Putting shoes on a table. In the UK, this is considered to bring extremely bad luck, traditionally the death of a person in the house. This is sometimes specified to only be unlucky when new shoes are put on a table
• In the British Navy it was traditionally considered unlucky to have a woman on board ship, although this may be a more practical matter. Having a naked woman on a ship was considered good luck, however.
• Among sailors it is considered unlucky to kill an albatross or a porpoise
• Among sailors it is considered bad luck to have anything blue aboard
• Saying "good luck" to an actor going onstage (the preferred expresion is: Break a leg)
• In theaters, "Macbeth" must not be uttered by anyone unless it is necessary to the show. For example, if the company is performing Shakespeare's Macbeth, one says "the Scottish Play" and refers to the characters as "Mackers" and "Lady Mackers"
• Sinistrality (being left-handed)
• Seeing one magpie
• A bird flies into one's window (a person in the family will die today, or has died last night). In some variants, it is believed to only be bad luck if the bird dies.
• Using a Ouija board; it is believed by some to attract bad spirits
• In some areas it is believed to be bad luck to kill a mockingbird; this becomes a part (albeit not a large part) of the story To Kill a Mockingbird, as well as inspiring the title.
• Cut your nails at night.

• In L. Frank Baum's The Patchwork Girl of Oz, a boy named Ojo discovers that he is known as "the Unlucky," but through the intervention of friends he makes over the course of the story he becomes Ojo "the Lucky" instead.
• Gladstone Gander, a fictional cartoon character, is dependent solely upon his good luck.
• Joe Btfsplk, a character in the Li'l Abner (Little Abner) comic strip by the cartoonist Al Capp is not only unlucky, he is shunned by the other characters as they suspect (with good reason) that this bad luck may be infectious.
• In Larry Niven's novel Ringworld, the character Teela Brown was the incredibly lucky result of a centuries-long breeding program initiated by the alien Pierson's Puppeteers directed to just such an outcome. The consequence of her state was that she'd led such a charmed and worry-free life that she was emotionally immature and unprepared for "harsh reality."
• In Terry Pratchett's Discworld series, luck is an anthropomorphic personification known as the Lady, who, while not a goddess, is powerful enough to be the rival of the god Fate. Her true name (hypothesized to be 'Lady Luck') cannot be uttered, and she is known to be attracted to the sound of rolling dice.
• Eugene Horowitz from Hey Arnold is known for the bad luck he constantly has, though his optimism always makes his personality win over it.
• Felix Felicis, a potion in the Harry Potter books, gives its drinker good luck. As a result, it is banned from examinations, sporting events and polls.
• Furrball the cat in Tiny Toon Adventures is a perpetually unfortunate feline, forever suffering mishaps, though frequently it's his own actions (i.e. overwhelming greed) that get him into trouble (not unlike mentor Sylvester the cat).
• Falkor from The Neverending Story is a Luckdragon who possesses uncanny luck with everything he does.
• In the Red Dwarf episode Quarantine a 'luck virus' existed.
• Fortune (or "Lady Luck"), a character in the video game Metal Gear Solid 2: Sons of Liberty, is implied to have extraordinarily good luck which apparently causes bullets to swerve away from her.
• Good Luck Bear, a character from the popular Care Bear TV Series and line of toys has is known almost entirely for his amazing luck. The 4 leaf-clover clover on his tummy says it all.
• Milfeulle Sakuraba of Galaxy Angel brims with such luck that she is repeatedly thrown out of casinos because she wins all the time, she finds winning lottery tickets on the ground, and can survive any ilk of danger because of her good fortune. However, this is balanced by periods in which Milfuelle has very terrible luck, causing her to want to be alone during these times.
• Huckleberry Finn — killing a spider or handling a snakeskin bring bad luck.
• Match Point by Woody Allen contains elements illustrating the importance of luck like a let in tennis.
• Althalus of David Eddings' The Redemption of Althalus is known as the world's luckiest thief. He perceives his luck to be in love with him, and associates it with a feeling he gets when he has been in any place for too long (ie. long enough for a bounty to be placed on his head).
• The Marvel Comics character Longshot of X-Men fame is supernaturally lucky so long as his motives are pure. Another Marvel character, the mutant Domino, also has a power which influences probabilities in her favor, and was in fact inspired by Longshot.
• The film Intacto is about individuals who have the ability to steal luck from others in order to compete in complex games of chance.
• Mat Cauthon in Robert Jordan's Wheel of Time series is considered to be uncannily lucky.
• In the Futurama episode "The Luck of the Fryrish", Fry goes in search of a seven leaf clover which brought him good luck back in his past life, before he was frozen.

• "Bad Luck" by Harold Melvin & The Blue Notes
• "Bad Luck" by Social Distortion
• "Bad Luck Blues" by Blind Lemon Jefferson
• "Bad Luck Streak in Dancing School" by Warren Zevon
• "Bad Moon Rising" by Creedence Clearwater Revival
• "Doggone My Good Luck Soul" by Hattie Hudson
• "Gwine To Have Bad Luck Seven Years" by Elizabeth Smith
• "Is it Luck" by Primus
• "Lady Luck Blues"by Weber / Williams, as sung by Bessie Smith
• "Luck Be a Lady" by Frank Loesser
• "Lucky" by Britney Spears
• "Born Under A Bad Sign" by Albert King
• "Lucky Man" by The Verve
• "With a Little Luck" by Wings
• "You Never Say Good Luck On Opening Night" from The Producers
• "I Should Be So Lucky" by Kylie Minogue
• "Lucky Star" by Madonna
• "Good Luck" by Basement Jaxx

• Curse
• Destiny
• Evil eye
• Folk religion
• Irrationality
• Karma
• Lady Luck
• Magic (paranormal)
• Probability
• Synchronicity
• Statistics
• Superstition
• Khalsa
• Malevolence
• Magical thinking
• Triskaidekaphobia

• Quotations on Luck
• Good Luck Charms Guide
• discover the world of lucky-clover leaves
• Inspiration: “Bad Luck? Good Luck? Who knows?” Chinese farmer story - Author Unknown