Ashling's Prerogative

Oracle Text

As Ashling's Prerogative enters the battlefield, choose odd or even. (Zero is even.)

Each creature with converted mana cost of the chosen value has haste.

Each creature without converted mana cost of the chosen value enters the battlefield tapped.

Card Rulings

10/1/2007 The “chosen value” is either “odd” or “even.” So either creatures with odd converted mana costs enter the battlefield tapped and creatures with even converted mana costs have haste, or vice versa.
10/1/2007 If a creature has X in its mana cost, that X is treated as 0 for the purposes of these effects. It doesn’t matter what the value of X was while the creature was on the stack.