A narrow opening, hole, or slit, as in a door or window. Also: a vacancy, position, or assignment: He got the slot as chief copy editor of the Gazette.
In the days before electronic gambling machines, a player’s odds of winning were determined by the frequency of symbols on each reel. The more symbols on a payline, the higher the payout. Some games also include wilds that can substitute for any other symbol and may offer a different payout if they appear on multiple lines. The pay table is usually listed on the face of the machine above and below the area containing the wheels.
But in the 1980s, manufacturers began using microprocessors to program their slot machines with “weighted reels.” By adding or subtracting weight to individual symbols, a manufacturer could alter the probability of each spin. This meant that, to a player, it might seem as though a particular symbol was “so close” to hitting, when in reality the odds were much less likely.
As casinos transitioned to electronic gambling, many replaced their army of slot mechanics with centralized computer servers hardwired into each machine. This allowed the casino to change the odds of each machine several times a day, instead of having mechanics physically resetting each machine. Using this method has saved money on labor costs and reduced air travel and fuel burn.