A principle, most often used in card magic, wherein multiple cards are placed into the deck at various locations, but out-jogged from the talon. The performer then pushes those cards into the deck at one time, causing any/all cards between the out-jogged ones to in-jog from the deck.
The Plunger Principle can be used as a rising card effect, a control, or as part of an effect, as in John Mendoza's Automatic Deck (1973).
There was some initial controversy over the invention of the original plunger principle used as a rising card effect.
A simple version of it first appeared in the September, 1931 issue no. 6 of Seven Circles Magazine by Lawrence Kam entitled Priceless Card Rise. The trick was published again in 1935, claimed this time by Burling Hull, in his Stage Magic, No. 3 (pp. 79-82). William Larsen, Sr., in the first issue of Genii 1936 September defended Jack McMillen as the inventor, as showing Larsen and T. Page Wright the trick in 1928.