Eye Of Judgment

Taken straight from Wikipedia's Distribution section on Collectible Card Games (http://en.wikipedia.org/wiki/Collectible_card_game#Distribution):

Specific game cards are most often produced in various degrees of scarcity, generally denoted as common (C), uncommon (U), and rare (R). Some games use alternate or additional designations for the relative rarity levels, such as super-, ultra-, or exclusive rares. Special cards may also only be available through promotions, events, or redemption programs. The idea of rarity borrows somewhat from other types of collectible cards, such as baseball cards, but in CCGs, the level of rarity also denotes the significance of a card's effect in the game, i.e., in general the more powerful a card is in terms of the game, the greater its rarity. A powerful card whose effects were underestimated by the game's designers may increase in rarity due to those effects; in later editions of the game, such a card's level of rarity might increase to reduce its availability to players. Such a card might even be removed entirely from the next edition, to further limit its availability and its effect on gameplay.

Most collectible card games are distributed as sealed packs containing a subset of the available cards, much like trading cards. Some of the most common distribution methods are:

Starter set - This is an introductory product which contains enough cards for two players and includes instructional information for the specific game. In order to speed the learning process, the card content is typically fixed and designed around a theme, so that the new players can start playing right away.

Tournament or starter deck - This contains enough game cards (usually 40 or more) for one player. It usually contains a random selection of cards, but with some basic elements so that it may be playable from the start.

Theme deck - Most CCGs are designed with opposing factions, themes, or strategies. A theme deck is composed primarily of cards that will work well together and is typically non-random.

Booster packs - This method of distribution is most similar to trading cards as the packs contain a random selection of roughly 8 to 15 cards.