Players play a Magic subgame, using their libraries as their decks. Each player who doesn't win the subgame loses half their life, rounded up.
Shahrazad has 1 printing, first in Arabian Nights (1993). It has 4 official rulings.
Legality
commander: banned
legacy: banned
vintage: banned
pauper: not legal
modern: not legal
pioneer: not legal
standard: not legal
brawl: not legal
Rulings
: At the start of the sub-game both players draw their initial hand (usually 7 cards). If one player has fewer cards than required, that player loses. If both have fewer than required, both players lose.
: Events in a Shahrazad sub-game do not normally trigger abilities in the main game. And continuous effects in the main game do not carry over into the sub-game.
: You randomly chose which player chooses to go first or draw first.
: At the end of a subgame, each player puts all cards they own that are in the subgame into their library in the main game, then shuffles them. This includes cards in the subgame’s Exile zone.