We'd be wasting your time if we attempted to categorize all the kinds of quality online slot machines. Every casino offers a wide selection of slots to attract gamblers. Slots come in hundreds of types and variations, from single line and 3 line, to 3 or 5 reel, and from bonus games to progressives, to mention just some.

It makes more sense to look at the common characteristics of slot machines.

Number of Reels

There are actually usually 3 or 5 reels in a slot machine. Early slots had only three reels. We remember them as "classic" or "regular" machines.

Today, 5 reel slots are common, and they generally feature more than one payline (see below).

Number of Rows

Slots machines feature one, two or several horizontal rows marking positions on the vertical reels.
Extra rows, usually one above and one below the payout display, tempt players with a view of how narrowly they might have missed a win.

Number of Pay Lines

There can be one or maybe more paylines crossing the reels.