# Casino 101

## Basic Terms

__ 1. House Edge:__The house edge is defined as the casino profit expressed as a percentage of the player's original bet. So if the House Edge is 99%, it means that on the long run, the player loses $1 for every $100 bet.

__ 2. Expected Value:__In probability theory the expected value (or expectation value, or mathematical expectation, or mean) of a discrete random variable is the sum of the probability of each possible outcome of the experiment multiplied by the outcome value (or payoff). Thus, it represents the average amount one "expects" as the outcome of the random trial when identical odds are repeated many times. Note that the value itself may not be expected in the general sense - the "expected value" itself may be unlikely or even impossible. The expected value of a cointoss is 0, if we win 1 on tails, and lose 1 on heads. If we would win 3 on tails, our expected value is 1 (0.5*3 - 0.5*1).

__ 3. Standard deviation:__In probability and statistics, the standard deviation is a measure of the dispersion of a collection of values. The standard deviation is usually denoted with the letter sigma. It is defined as the root-mean-square (RMS) deviation of the values from their mean. In casino terms the standard deviation is usually very much linked to the number of possible outcomes. E.g. Blackjack has lower standard deviation than Roulette.

__ 4. Wagering Requirement or simply Wager:__ The amount we have to bet in total in order to withdraw our bonus.