Luck or fortuity is good or bad fortune in life caused by accident or chance, and attributed by some to reasons of faith or superstition, which happens beyond a person's control. The term luck is pervasive in common speech. There are at least two senses people usually mean when they use the term, the proscriptive sense and the descriptive sense. In the proscriptive sense, luck is the supernatural and deterministic concept that there is a force. This Force proscribes that certain events occur very much the way the laws of physics will proscribe that certain events occur. It is the proscriptive sense that people mean when they state that they do not believe in luck. In the descriptive sense, luck is merely a descriptive name we give to events after they occur which we find to be fortuitous. Cultural views of luck vary from perceiving luck as a matter of random chance to attributing to luck explanations of faith or superstition. For example, the Romans believed in the embodiment of luck as the goddess Fortuna, while the atheist and philosopher Daniel Dennett believes that luck is mere luck rather than a property of a person or thing. Lucky symbols have widespread global appeal. They are always meaning a form of superstition. 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 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 differently by different individuals. Famous Swiss psychiatrist, Carl Jung, who founded analytical psychology, coined the term synchronicity, which he described as a meaningful coincidence. Christianity and Islam 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 person to another; however, most acknowledge providence as at least a partial, if not complete influence on luck. Christianity, in its early development, accommodated many traditional practices which at different times, accepted omens and practiced forms of ritual sacrifice in order to divine the will of their supreme being or to influence divine favoritism. The concept of Divine Grace as believers describe it closely resembles what others refer to as luck. Mesoamerican religions, such as the Aztecs, Mayans and Incas, had particularly strong beliefs regarding the relationship between rituals and luck. 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 and feared, based on their ability to cause good or bad fortune for those in villages near them.

Online poker is the game of poker played over the Internet. It has been partly responsible for a dramatic increase in the number of poker players worldwide.

Traditional or brick and mortar, live venues for playing poker, such as casinos and poker rooms, may be intimidating for novice players and are often located in geographically disparate locations. In addition, brick and mortar casinos are reluctant to promote poker because it is difficult for them to profit from it. Though the rake, or time charge, of traditional casinos is often high, the opportunity costs of running a poker room are even higher. Brick and mortar casinos often make much more money by removing poker rooms and adding more slot machines.

Online venues, by contrast, are dramatically cheaper because they have much smaller overhead costs. For example, adding another table does not take up valuable space like it would for a brick and mortar casino. Online poker rooms also allow the players to play for low stakes as low as 1¢/2¢ and often offer poker free roll tournaments where there is no entry fee, attracting beginners and/or less wealthy clientele.

Online venues may be more vulnerable to certain types of fraud, especially collusion between players. However, they have collusion detection abilities that do not exist in brick and mortar casinos. For example, online poker room security employees can look at the hand history of the cards previously played by any player on the site, making patterns of behavior easier to detect than in a casino where colluding players can simply fold their hands without anyone ever knowing the strength of their holding. Online poker rooms also check players' IP addresses in order to prevent players at the same household or at known open proxy servers from playing on the same tables

Typically, online poker rooms generate the bulk of their revenue via four methods. First, there is the rake. Rake is collected from most real money ring game pots. The rake is normally calculated as a percentage of the pot based on a sliding scale and capped at some maximum fee. Each online poker room determines its own rake structure. Since the expenses for running an online poker table are smaller than those for running a live poker table, rake in most online poker rooms is much smaller than its brick and mortar counterpart.

Second, hands played in pre-scheduled multi-table and impromptu sit-and-go tournaments are not raked, but rather an entry fee around five to ten percent of the tournament buy-in is added to the entry cost of the tournament. These two are usually specified in the tournament details as, e.g., $20+$2 $20 represents the buy-in that goes into the prize pool and $2 represents the entry fee, de facto rake. Unlike real casino tournaments, online tournaments do not deduct dealer tips and other expenses from the prize pool.

Third, some online poker sites also offer games like blackjack or side bets on poker hands where the player plays against the house for real money. The odds are in the house's favor in these games, thus producing a profit for the house. Some sites go as far as getting affiliated with online casinos, or even integrating them into the poker room software.

Fourth, like almost all institutions that hold money, online poker sites invest the money that players deposit. Regulations in most jurisdictions exist in an effort to limit the sort of risks sites can take with their clients' money. However, since the sites do not have to pay interest on players' bankrolls even low-risk investments can be a significant source of revenue.

Differences compared with conventional poker

There are substantial differences between online poker gaming and conventional, in-person gaming.

One obvious difference is that players do not sit right across from each other, removing any ability to observe others' reactions and body language. Instead, online poker players learn to focus more keenly on betting patterns, reaction time, speed of play, use of check boxes/auto plays, opponents' fold/flop percentages, chat box, waiting for the big blind, beginners' tells, and other behavior tells that are not physical in nature. Since poker is a game that requires adaptability, successful online players learn to master the new frontiers of their surroundings.

Another less obvious difference is the rate of play. In brick and mortar casinos, the dealer has to collect the cards, shuffle, and deal them after every hand. Due to this and other delays common in offline casinos, the average rate of play is around thirty hands per hour. However, online casinos do not have these delays. The dealing and shuffling are instantaneous, there are no delays relating to counting chips for a split pot, and on average, the play is faster due to auto-action buttons where the player selects his action before his turn. It is not uncommon for an online poker table to average ninety to one hundred hands per hour.

Online poker is considerably cheaper to play than conventional poker in many ways. While the rake structures of online poker sites might not differ fundamentally from those in brick and mortar operations, most of the other incidental expenses that are entailed by playing poker in a live room do not exist in online poker. An online poker player can play at home and thus incur no transportation costs to get to and from the poker room. Provided the player already has a somewhat modern computer and an Internet connection, there are no further up-front equipment costs to get started. There are also considerable incidental expenses once on a live poker table. In addition to the rake, tipping the dealers, chip runners, servers and other casino employees is almost universally expected, putting a further drain on a player's profits. Also, whereas an online player can enter and leave tables almost as he pleases, once seated at a live table a player must remain there until he wishes to stop playing, or else go back to the bottom of the waiting list. Food and beverages at casinos are generally expensive even compared to other hospitality establishments in the same city let alone compared to at home and casino managers feel little incentive to comp poker players.