Straight slots are a broad category of slot machines. They feature several columns of symbols that spin on each play, settling on a particular combination. A payout table, printed on the machine, indicates which combinations of symbols count as a win, and how much the player will win if those combinations appear. The required denomination to play typically ranges from 25 cents to one dollar.
Wildcard slots are straight slots that use a wildcard symbol, which can take the place of any symbol the player needs to complete a matching line. This increases the odds of winning, but wildcard slots may feature a lower payout table.
A multiplier is a straight slot machine that pays out based on the number of coins (or credits) the player inserts. The total winnings are multiplied by the number of credits. For example, a $5 win pays $5 with a single credit, $10 with two credits and $15 with three credits. The player can choose one, two or three credits for each pull of the handle and the number of credits does not affect the odds of winning.
Bonus multipliers are straight slots that work much like a multiplier but offer an additional bonus for wins when the player has played the maximum number of credits. The amount of the bonus is listed on the payout table.
A buy-a-pay slot machine is another type of straight slot that uses a more complicated table for determining winnings based on bets. Players can choose from more than one payout table based on how many coins they bet. Additional bets also allow the player to win with different combinations. Players who bet a low amount but win on one of the lines they did not bet don't receive the winnings that they would have if they had bet the maximum.
Progressive slots are different than all types of straight slots in that they feature a progressive jackpot that increases over time. The increasing jackpot is based on a small percentage of each bet made in a group of machines or across an entire casino. Once a player hits the progressive jackpot, the amount resets and begins building again.