Enchantment, 1B (2) If a player would draw a card except the first one he or she draws in his or her draw step each turn, that player discards a card instead. If the player discards a card this way, he or she draws a card. If the player doesn't discard a card this way, he or she puts the top card of his or her library into his or her graveyard.1
Illus. Heather Hudson
If you cast a spell to draw extra cards (such as Ancestral Recall or Wheel of Fortune) at some time outside the draw step, this affects all the cards drawn. During your draw step, the first card drawn is not affected. [bethmo 1994/06/15]
Only affects the drawing of cards. It does not affect spells like Demonic Tutor, Millstone, or Petra Sphinx which affect the library but do not say "draw" a card. [bethmo 1994/06/22]
If X cards are drawn as the resolution of a single spell/ability, then the game treats this as X separate "draw one card" actions. So for each card that would be drawn, apply the effect. [D'Angelo 2000/07/06]
The effect is cumulative. If you have two of these out, each of them will modify on each draw (after the first one if during the draw step), and will cause the player to discard or to "mill" a card from their library. As they resolve in order, the player must discard if possible. Once the player fails to discard and instead "mills" a card, all further effects of additional Chains of Mephistopheles will not do anything. This is because the "mill" also replaces the draw effect and the player is no longer drawing a card. [WotC Rules Team 1996/12/03] You handle them in order. Each one makes you discard first and then continue or else mill a card and lose the draw.
This is a replacement effect (see Rule 419). [D'Angelo 1999/02/03]
Cards which are drawn as a cost are affected by this card because replacement effects can alter the payment of costs (see Rule 419). [D'Angelo 1999/05/01]
Extended tournaments (see Rule 803) have always banned this card.
Legends
(Rare)