Online casinos generally offer odds and payback percentages that are a bit higher than land-based casinos.
Some online casinos claim higher payback percentages for slot machine games, and some publish payout percentage audits on their websites. Assuming that the online casino is using an appropriately programmed random number generator, table games like blackjack have an established house edge. The payout percentage for these games are established by the rules of the game.
Many online casinos rent or buy their software from companies like CryptoLogic Inc (now Amaya), International Game Technology,, Playtech, and Realtime Gaming.