Whatever the case, it's been a key component of Standard, Pioneer, Alchemy, Historic, and Explorer decks that run Islands
702.187b: Mayhem [cost] means As long as you discarded this card this turn, you may cast it from your graveyard by paying [cost] rather than paying its mana cost. Casting a spell using its mayhem ability follows the rules for paying alternative costs in rules 601.2b and 601.2fh
Jace, Wielder of Mysteries Like Laboratory Maniac, Jace, Wielder of Mysteries wins you the game if you would draw a card but your library is empty
Aether Storm in Homelands had the text: No summon spells may be cast. In future reprints, it changed to creature spells cant be played. The first version of Future Sight stated that you can play the top card of your library. This terminology caused some confusion because play has multiple meanings: in play, play a card, play with the top of your library revealed, and so on
Rampaging Ferocidon is my top pick for the best dinosaur creature in MTG