Impulse draw is an informal term for effects, most commonly in red, that exile cards from a library and allow them to be played for a limited amount of time. It provides card advantage without functioning exactly like conventional card draw.
Wrenn's Resolve offers a straightforward version, while Prosper, Tome-Bound rewards playing cards from exile with Treasure. Faldorn, Dread Wolf Herald takes the strategy further by creating Wolves whenever cards are played from exile.