Editing Magic: The Gathering Gameplay Principles (section)

==Card advantage==
Whoever has the most cards win. This is actually surprisingly bit messy and blurry.  Tokens are often considered cards in their own right. Cards in hand are almost always considered cards for the sake of card advantage. Cards with flashback in a graveyard are sometimes considered cards in hand for the sake of card advantage. A card draw spell sets a player back in tempo but helps put that player ahead in card advantage. Arguably, looting (draw and discard, sometimes also refers to rummaging) and rummaging (discard and draw) is card advantage. Looting and rummaging '''do not''' help card quantity, but improve card quality. Same goes for scry (except of course the time between you decide the you like the card on top of your deck and getting scry:1, those are pretty much worthless). Certain interactions between players can put one ahead or behind in card advantage. For example, if a creature is double blocked, and all involved creatures die, this is a case of a “2 for 1” and it puts the blocked/attacking creature’s controller ahead in card advantage. Card Advantage is considered less important in short games.