Possessed Portal and dredge

[Maveric78f]

How do possessed portal and the dredge ability interact?

[cdr]

Possessed Portal 8
Artifact
If a player would draw a card, that player skips that draw instead.
At the end of each turn, each player sacrifices a permanent unless he or she discards a card.


Dredge: Dredge is a static ability that functions only while the card with dredge is in a player's graveyard. "Dredge N" means "As long as you have at least N cards in your library, if you would draw a card, you may instead put N cards from the top of your library into your graveyard and return this card from your graveyard to your hand." A player with fewer cards in his or her library than the number required by a dredge ability can't put any of them into his or her graveyard this way. See rule 502.47, "Dredge."


419.9. Interaction of Replacement or Prevention Effects

419.9a. If two or more replacement or prevention effects are attempting to modify the way an event affects an object or player, the affected object's controller (or its owner if it has no controller) or the affected player chooses one to apply. If any of those effects are self-replacement effects (see rule 419.6d), one of them must be chosen. If not, but any of those effects would modify under whose control an object would come into play, one of them must be chosen. Otherwise, any of the applicable effects may be chosen. Once the chosen effect has been applied, this process is repeated (taking into account only replacement or prevention effects that would now be applicable) until there are no more left to apply. If two or more players have to make these choices at the same time, choices are made in APNAP order (see rule 103.4).

Example: Two permanents are in play. One is an enchantment that reads "If a card would be put into a graveyard, instead remove it from the game," and the other is a creature that reads "If [this creature] would be put into a graveyard from play, instead shuffle it into its owner's library." The controller of the creature that would be destroyed decides which replacement to apply first; the other does nothing.

Two replacement effects ("instead") trying to modify the same event; the player drawing the card chooses which to apply first, after which the other will no longer be applicable since a card is no longer being drawn.