Three liners take three coins and should always be played with three coins. The first coin pays on the center line, the second coin pays on the top and center lines and the third coin pays on all three lines. The other standard variation is the five line machine. This has three lines the same as the three liner above but also has two diagonal lines making a total of five pay lines. If you are going to play these you should play the maximum five coins.
Most machines have three reels but there are exceptions.
There are novelty machines with two reels, and the odd four reeler. The big berthas usualy have from three to several reels and are normaly in the dollar range of play, taking up to three dollars at a time. These should not be taken too seriously. A recent innovation is the single line diamond pay out. If the proper symbols appear in a diamond shape on the face of the machine you win.