What it does
Dredge gives you an alternative way to draw: whenever you would draw a card, instead you may put a specified number of cards from the top of your library into your graveyard, then return the dredge card from your graveyard to your hand. It's optional each time, and it replaces that draw entirely—you don't draw and mill, you choose one or the other.
The big nuance: dredge only works from your graveyard, and it replaces a draw, so you need to be drawing a card for the option to appear. If your library has fewer cards than the dredge number, you can't dredge that card. Also, replacing a draw means card-draw triggers ("whenever you draw") don't fire.
In Commander, dredge fuels graveyard strategies—reanimation, self-mill payoffs, and recursion engines—while turning every draw step into selective graveyard stocking. Watch your library count, since aggressive dredging can deck you out.













