Land Flood Plain enters the battlefield tapped.
Uncommon
{T}, Sacrifice Flood Plain: Search your library for a Plains or Island card and put it onto the battlefield. Then shuffle your library.
Illus. Pat Morrissey

10/4/2004: Because the "search" requires you to find a card with certain characteristics, you don't have to find the card if you don't want to.
Legal in Vintage (Type 1)
Legal in Legacy (Type 1.5)
Legal in Classic (MTGO)
Legal in Commander