Online casinos can for certain games offer better odds than land casinos on slots and other formats where the chance of winning is determined by the house. Table games like blackjack have an established house edge; for a given set of rules, they offer the same payout, online or offline. Reliability and trust are hard to establish. To fix this issue, many online casinos purchase their software from well-known companies such as Wager Works, Microgaming, Playtech, and Cryptologic, though a little research into credentials of any e-commerce website you intend to use is common sense. These software companies use a random number generator to ensure that the numbers, cards or dice appear randomly. All reputable companies operating in a regulated environment use robust random number generators.
See the discussion of the legality for online gambling of playing at an online casino.
Online casinos can be divided into two groups based on their interface: on-line casinos and download-based casinos. Some casinos offer more than 1 interface.
Web-based online casinos
Games are mainly represented in the browser plugins Macromedia Flash, Macromedia Shockwave, or Java and require browser support for mentioned plugins. Also, bandwidth is needed since all graphics, sounds, and animations are loaded through the internet via the plugin. A very few casinos allow games played through a plain HTML interface.
Download-based online casinos
Download-based online casinos are the most common casino websites. An advantage of these compared to online casinos is speed, since it doesn’t have to load graphics from the Internet because all multimedia is inside the downloaded software. On the downside, there’s an initial download and the need for the setup of this program, and the chance of the program containing malware (though this is extremely uncommon).
A typical choice of games available at an online casino might include blackjack, roulette, baccarat, craps, pai gow poker, video poker, and slot machines.
Many online casinos offer large bonuses, often a “100% match bonus”. For example:
100% up to $100
Must wager 25 times the deposit and bonus before withdrawing
Wagers on baccarat, craps, roulette, and sic bo won’t count towards meeting wagering requirements
For this specific example, this might mean that a player depositing $100 would start with $200 in his account. He must make $5000 ($200 × 25) in wagers before withdrawing. This can be played in a game like a blackjack.
Some simple arithmetic shows that if the player leaves after meeting the requirements, he has a huge edge. By way of example, the house edge in blackjack is around or less than 0.5% at most online casinos. $5000 × 0.005 = $25. Therefore, the player expects to show a $25 reduction — however, he was given a $100 bonus. As a result, the player’s expected profit is $75, a massive 75% advantage. Usually, taking advantage of such a promotion is the only means to get an edge over the casino.
This has often led to players playing at casinos to take the bonus, and leaving after the wagering requirements are satisfied. These players are called by (and have adopted with pride) a variety of labels such as “advantage players”, “bonus hunters”, “bonus abusers”, and, perhaps the most vulgar, “bonus whores”. Strictly speaking, this behavior is usually prohibited by the casino, because their terms usually dictate that players may play for recreational purposes only. In practice, players are rarely caught doing this, and usually, when they are, they simply have their promotion privileges revoked.
A participant who wants to do this in a significant number of online casinos must be careful. Some casinos are rogues (see below) and don’t pay. Others have terms and conditions that aren’t favorable to the participant, such as most bonuses that are restricted to slots.
Cheating software appears to be quite rare. There are some casinos that have been mathematically proven to cheat, such as Casino Bar (evidence by Michael Shackleford and others). Some players often accuse certain popular software brands of casinos of cheating, for example, Boss Media, Cryptologic, and Playtech, but they are likely “finding” patterns that aren’t actually there, as tests for cheating at these casinos has never turned up positive. This doesn’t mean that all software providers are honest (for example, Elka System/Oyster Gaming software is known to cheat, also confirmed by Michael Shackleford), but the most popular software is more likely than not.
Although there’s the occasional rogue casino, sometimes it’s the players that are deceitful or reckless. Among the most common cases is that a participant who signs up for multiple accounts at a casino using fake names to reap the bonus more than once. Another player may use Adobe Photoshop or a similar instrument to control the images of a slot machine screenshot to attempt and fool the casino into believing she hit a jackpot and did not get paid for it. These are gross violations of the conditions of service of the casino and are frowned upon, even by many “bonus hunters”. Casinos don’t tolerate such behavior and will often lock the account or accounts of the player responsible, and may inform other casinos or the software supplier to keep the player from different casinos.