Quick Guide: Dublin's light rail systems

The first thing to realize is that Dublin actually has two light rail systems and a total of three lines (which don't connect). 

Luas has two lines: red and green.  For tourists the more useful line is the red line which in the touristy areas runs mainly east/west north of the Danube.  The Luas rarely drops you directly at an attraction, but you can easily walk to many attractions from the Luas.  Luas runs above ground and you can see the tracks in the central areas.  Given that Luas runs above ground, you get to enjoy plenty of views of Dublin from the train

 The Luas has two unconnected lines, the green and the red line. It is a zone based system so prices vary by zone.  It was un-gated, at least at all the stations I went to.   You buy your tickets on the platform.  Be sure to hold onto them as they can do ticket checks on board.  

The other light rail system is the DART which mainly runs north and south.  The DART is more of a commuter train and depending on where you are staying you may not find yourself using the DART.  From the DART Pearce Station is a great station to exit at if you are trying to get to attractions in the center of the city.  You can get there by walking through Trinity College. 

If you need to switch from the Red line of LUAS to the DART (or the reverse) you can switch trains at Connolly station where you will need to buy a ticket for the other system.