RNG - Random Number Generator, a computer chip placed inside the online slot machine by the manufacturer which randomly selects hundreds of numbers and symbols every second, faster than you can pull that handle or push that spin button; working even when the machine is idle. Each number corresponds to a certain symbol combination that is randomly chosen after the first coin is dropped or credit played. Fewest programmed combinations are for the top jackpot. This program computer chip is also designed to determine that particular slot's average payout %. No slot machine will pay back its preset payoff percentage rate every time. because the final outcome of every spin is randomly selected.
Reels: number of wheels/reels showing on slot with symbol combinations imprinted: usually three, but some slots have five.

Online Slot Schedule: posted information on front of slot tells you what type of slot, denomination and win amounts possible for each coin played. Read this!
Loose/Tight online slots -- Loose slots will have better payoffs to a "certified" high of 100%, on average over a period time. A machine will have a symbol, let's say 2-3 cherries, which pays a couple of coins. These cherries will replace a symbol that doesn't pay, and presto you have a loose machine. Reverse this procedure for a tight slot. In other words, the more paying symbols a machine has, the greater the probability of payouts - thus a loose slot.
Up/Down Slot Machine Online Cycle: Online Slot's average payoff percentage rate applies over the long haul, as long as one year. Therefore a slot with a 98% payoff percentage rate will sometimes pay off at 130% and other times at 50%..sometimes at 28% and other times at 502%. The lower percentages indicate a down cycle and the higher numbers an up cycle. Also known as Sizzling/Sputtering Slot.
Slots Online Drop/Hold: Drop: amount of money through the slot. Hold: amount not paid out as wins; these two numbers determines slot's payout %.
Slot Machine Testing; playing through a single roll of coins without using accumulated credits to determine possible payout % for selected slot.
Slot-mix or Slot Machines Placement: Generally the loosest slots are placed in high-traffic areas where passersby's can see other players winning often. Important to analyze a slot's location, in other words -- crack that slot-mix code -- start at the main cashier/change booths in the casino.
Don't play two machines at a time, side-by-side; tight slots are placed next to loose ones. What one gives, the other takes away. Also don't play next to a winning machine.

Slot Machine Types/Versions: Basic, straight or "flat-top" slots have a constant top jackpot payout that does not change no matter how much the machine is played.
Multiplier Online Slots pays for certain symbols on a graduating scale. On a three reel, you get 5 coins for a "cherry" playing 1 coin, 10 pay for 2 coins and 15 pay for 3 coins. The payouts for playing 1 coin are much smaller than if you played maximum coins.
Bonus Multiplier Slots online offer larger top jackpots as incentive to play max coins. The top jackpot symbol, e.g. 7's will only pay with max coins. This is important for those players who have lined up winning 7's only to find their single coin bet did not win. Fess up folks, we have all done this; be forewarned. Multiplier "Wild" Symbol Slots: newest versions with bonus credits, scatter pays and free spins include: Multi Jackpot, Triple Double Diamond, Five Times Pay, Cherries 'R' Wild, and Triple Red White & Blue. Same scenario, max coins produce larger winnings.
Buy-your-Pay: Each coin played triggers the posted symbol payout. E.G., if you play one coin, you only trigger 'cherry' pays. Two coins triggers 'cherries' and 'bars'. Is there a worse feeling that lining up all three top jackpot symbols with only one coin played?
Double Machines: pays double or triple with winning combinations of certain symbols lined up, e.g. Double Diamond, Triple Diamond, RWB 7's.
Signature Slots Online: casinos own brand of slots, generally looser creating the desired PR for the casino.
Progressive Slots Online: offer growing jackpots dependent upon amount of monies played through the linked bank/carousel slots. A larger bankroll is required and all progressives are at least three coin max slots with two jackpot levels - primary and secondary. When either jackpot wins, values are reset to minimums for each. Max play is mandatory here.
Bonus Video Slots Online: the latest gaming trend are the most graphically loaded, glitziest slots to come along in a long time. Bonus Slots Online are described as "branded machines", entertainment-content" "brand recognition", "participation" games, "interactive" & "banking" slots. The name Bonus Slots says it all; an opportunity to go to a 'second chance' bonus round where the real money is. Regular online slot players will recognize the names: Monopoly, Elvis, Let's Make a Deal, Wheel of Fortune, Piggy Banking', Reel 'Em In. You are on sensory overload with Bonus Slots offering at least 25 symbols filling up the screen in front of you. Multiple pay-lines with as many as 5 or 9 pay lines. Many versions come in penny denominations; also nickel, quarter and dollar.
You are back in the penny arcades of your youth and enjoying every minute.
CALL ATTENDANT: The slot of your dreams has just lined up a hand-pay. You scream, clap your hands, jump up and down and wait for those peeled off bills to arrive. Ask for a comp at that time.
Short Win: large jackpot win after a small cash outlay - happens often.
Sound of Rain: coins dropping into the holder after a payout.
Slot Club Cards/Comps: Sign up for freebies and reap the benefits.
Slot Talk: information traded between other players, change people and slot hosts to locate winning slots and improve your slots education.
Hit and Run Winner: my most often repeated advice. If a online slot machine does not pay after 3-5 maximum coin spins, move on.
Class dismissed, onward to those 'raining' slots online..