The Easycard is a prepaid card which can be used to pay for the MRT and bus trips. It makes traveling much easier and keeps you from having to dig for change everytime you want to go somewhere. I would definately recommend getting one.
Price:

The Easycard costs 500nt for adults. The card starts off with a value of 400nt so the actual cost of the card is only 100nt. You get an additional bonus because the cost of every trip is discounted 20%
Where to buy:
You can purchase your Easycard either at the MRT station or at one of the many convenience stores in Taipei (7-11, Niko Mart, OK, Family Mart, Hi-life).

If a store sells the card they are supposed to display a logo like this.
Types of Easycard:
-
Adult:
Standard fare for general public
-
Student:
For students, military personnel and police
-
Charity:
For disabled residents of Taipei City or County
-
Escort:
For the person accompanying a Charity EASYCARD user
-
Senior:
For senior citizens 65 and older, residents of Taipei City or County
-
Concessionaire:
For children, with a height between 115cm to 145cm, and senior or disable people who are not residents of Taipei City or County (Concessionaire cards are available at the following convenience stores: 7-ELEVEN, Family Mart, Hi-Life, Niko Mart and OK.)
Recharge your Card:

You can recharge your Esaycard in any of the MRT stations. Just insert your card, insert your money and your on your way. There is also a card reader located in each MRT statin where you can check your balance by placing your card on the sensor.
Using your Card:

The Easycard has a wireless electronic chip in it which sends a signal to the reader. It doesn't work with a magnetic strip so you don't have to worry about keeping it away from magnets. When using your card don't stick it in the slot, just swipe it over the Easycard logo on the entryway.