Electro-mechanical Slot Machine: A machine that uses both mechanical and electronics to operate. These slot machines have either a push betting button, or the pull arm that can be used to spin the wheel.

Eye in the Sky: A term referring to the surveillance cameras used in casinos.

Edge: The advantage one player has over another.

Even Money: A ratio win rate of 1:1 that pays back the same amount wagered along with the original bet.

Expected Payout: When placing a bet, the expected payout is money that can be expected to be won over a period of time. Usually this is determined by the amount of the bet that is being placed or on a max bet.

Expected Win Rate: A slot machine term used for the rate at which a player can expect to win their money back over a period of time