Reveal the top X cards of your library. You may put any number of permanent cards with converted mana cost X or less from among them onto the battlefield. Then put all cards revealed this way that weren't put onto the battlefield into your graveyard.
11/17/2017 If you have fewer than X cards in your library, you reveal all of them.
11/17/2017 If a card in a player’s library has in its mana cost, X is considered to be 0.
11/17/2017 A permanent card is an artifact, creature, enchantment, land, or planeswalker card.
11/17/2017 If a card in your library has no mana symbols in its upper right corner (because it’s a land card, for example), its converted mana cost is 0. Such cards can always be put onto the battlefield with Genesis Wave.
11/17/2017 You don’t have to put permanent cards revealed this way onto the battlefield if you choose not to, regardless of their converted mana costs.
11/17/2017 All of the permanents put onto the battlefield this way enter at the same time. If any have triggered abilities that trigger on something else entering the battlefield, they’ll see each other.