Cards are also split into different types: including characters, songs, items, actions and locations
Milling a card means putting the top card of your library into your graveyard if theres no card to put into the graveyard, no cards were milled
For example, discarding easily recurred creatures, such as Gutterbones, easily pays the cost
You can't one-for-one remove cards with counterspells and targeted removal, or use a wrath to sweep a few things and expect to be ahead in the current Standard meta
Fond of fetch lands, or simply milling cards into the graveyard
(Source: Hickey on an Unlimited Dragon Whelp) The Problem with Unlimited and Roller Lines Unlimited suffers from a series of misprints that Alpha and Beta were mostly untouched of: Roller Lines