It’s like the search for the Holy Grail. Before the days of King Arthur and the roundtable of Camelot, people have hunted for this holy relic and its promise of eternal life. Just the same, consumers the world over have searched for their lives for the holy grail of the credit card world: a card with 0 annual percentage rates, or no interest at all. Such a card could provide eternal shopping, and a life without fear of debt.

The reality of the situation, however, may be slightly different. Don’t get us wrong. A card with 0 annual percentage rate is a beautiful thing. It allows you to carry debt on the card without fear of swamping your finances with interest payments. On the other hand, the 0 annual percentage rate is not a free ride to spend to excess. After all, most of these 0 annual percentage rate, or 0 APR cards, have a time limit. The carriage, so to speak, eventually turns back into the pumpkin, and then you could be left holding the bag with a maxed out credit card and a new APR of, say, 22 percent.

So, what exactly is a 0 APR credit card? Is it such a great deal anymore, or should you not chase after the holy grail? It depends, as with any great decision. If you plan to be making a lot of heavy purchases soon—such as to decorate a new house—you may want to find yourself a 0 APR card, but do so with the understanding that you must be able to pay that baby off when the 0 annual percentage rate special wears off.

Don’t just jump at any 0 annual percentage rate card, though. There are always other considerations to make when you’re on the market for a new credit card. For instance, how widely is the new card going to be accepted. If you travel a lot, this is important to know. MasterCard and Visa are the two most widely accepted brands of cards on the market, with 17 million and 16.2 million locations respectively.

And of course, every credit card now has a rewards program. What sort of rewards programs would suit you best—one that involves cash back and discounts on every purchase, or would you rather earn points toward travel and other prizes? Plus, no matter what the rewards are, compare the ratio of earned points to dollars spent. The higher this ration, the better the rewards program is, no matter what the rewards are.

Lastly, check the fees on these 0 APR cards. Is there an annual fee, a cash transfer fee, late fees, stiff penalties, etc.? These also could help you make up your mind about the card.